When it comes to mergers and acquisitions, bigger doesn’t always mean better - the examples we included in our list of the biggest M&A failures is evidence of that.

In fact, all things being equal, the bigger a deal becomes, the bigger the likelihood that the buyer is overpaying for the target company. But whether you like mega deals or not, we cannot afford to ignore them. 

At DealRoom, we help companies evolve and streamline multiple large and successful M&A deals each year. In this article, we collected some of the biggest deals in history.

In this article: 

• Biggest mergers and acquisitions examples list
• Lessons from successful and failed mergers and acquisitions
• Emerging trends in mergers and acquisitions
• Frequently asked questions
• Final thoughts

Related: Recent M&A Deals and 8 Biggest M&A Deals in History (so far) and 8 Biggest Upcoming M&A Deals in 2023 (so far)

Biggest mergers and acquisitions examples list

Reading this list, it can seem that the biggest deals are doomed to failure (at least from the perspective of their shareholders). But thankfully, that just isn’t the case. Some of the biggest M&A transactions of the past 30 years have been outstanding successes.

Many of these deals have achieved what they set out to do at the outset - to reshape industries on the strength of a single deal.

With that in mind, let's take a closer look at 35 companies that recorded the largest mergers and acquisitions in history.

1. Vodafone and Mannesmann (1999) - $202.8B ($389.42B adjusted for inflation)

As of March 2024, the takeover of Mannesmann by Vodafone in 2000 was still one of the largest acquisitions ever made. Worth ~$203 billion at that time, Vodafone, a mobile operator based in the United Kingdom, acquired Mannesmann, a German-owned industrial conglomerate company.

This deal made Vodafone the world’s largest mobile operator and set the scene for dozens of mega deals in the mobile telecommunications space in the years that followed. This deal is still considered as the biggest acquisition in history.

2. Shenhua Group and China Guodian Corporation (2017) - $278B ($361.17B adjusted for inflation)

The merger between Shenhua Group and China Guodian Corporation is the biggest example of a merger of equals that happened in 2017. Shenhua Group is China’s largest coal provider, while China Guodian Corporation is one of the top five electricity producers.

This $278 billion merger created the world’s largest power utility company by installed capacity. The goal of the merger was to create a balanced energy portfolio between coal power and renewable energy. This is to align with China’s broader environmental and economic objectives.

3. AOL and Time Warner (2000) - $182B ($340.16B adjusted for inflation)

When we mentioned at the outset of this article that ‘big doesn’t always mean better’, the famous merger of AOL, a U.S.-based internet service provider, and Time Warner, an American cable television company, in 2000 is a case in point. 

In little over two decades, the deal has become cemented as the textbook example of how not to conduct mergers and acquisitions. It featured everything from overpaying to strong cultural differences and even, with the benefit of hindsight, two large media companies who just weren’t sure where the media landscape was headed. 

The merger's valuation came crashing down after the dot-com bubble burst just two months after the deal was signed. The deal, which is to be known as the largest merger in history, fell apart in 2009, 9 years later after it was originally signed.

4. ChemChina and Sinochem (2018) - $245B ($311.84B adjusted for inflation)

The ChemChina and Sinochem merger was part of the Chinese government’s bigger plan to strengthen their competitiveness in the global stage by reducing the overall number of its state-owned enterprises through merging its biggest companies to create a larger firm.

This specific merger created the world’s largest industrial chemicals company, known as Sinochem Holdings, which surpassed major global competitors like BASF in North America in terms of scale and market presence.

5. Gaz de France and Suez (2007) - $182B ($283.67B adjusted for inflation)

France loves its national champions - the large French companies that compete on a world stage, waving the tricolor. It was no surprise then, when Nicholas Sarkozy, President of France in 2007, stepped in to save this merger.

That’s right - a President playing the role of part-time investment banker. These days, Suez is one of the oil and gas ‘majors’, although the fact that the company’s share price hovers very close to where it was a decade and a half ago tells us everything of what investors thought of the deal.

The deal, one of the biggest mergers ever in energy, created the world’s fourth largest energy company and Europe’s second largest electricity and gas group. The merged companies created a diversified, flexible energy supply stream with a high-performance electricity production base.

6. Glaxo Wellcome and SmithKline Beecham merger (2000) - $107B  ($199.99B adjusted for inflation)

The merger of the UK’s two largest pharmaceutical firms in 2000 led to what is currently the 10th largest pharmaceutical firm in the world, and is one of two British firms in the top 10, along with AstraZeneca, which ranks 7th.

However, like several deals on this list, it wasn’t received particularly well by investors and at the time of writing is trading at about 25% less than at the time of the merger.

This, and a range of bolt-on acquisitions in the consumer space over the past decade, may explain why the company is planning to split into two separate companies in the coming years.

7. Verizon and Vodafone (2013) - $130B ($178.11B adjusted for inflation)

Vodafone has been involved in so many transactions over the past 20 years that they should be getting quite efficient at the process at this stage. The $130B deal in 2013 allowed Verizon to pay for its US wireless division.

At the time, the deal was the third largest in history - two of which Vodafone had partaken in. From Verizon’s perspective, it gave the company full control over its wireless division, ending an often fraught relationship with Vodafone that lasted for over a decade, and also allowed it to build new mobile networks and contend with an increasingly competitive landscape at the time.

From Vodafone's point of view, the acquisition cut the company value roughly in half, to $100 billion. The business acquisition also moved Vodafone from the second largest phone company in the world down to fourth, behind China Mobile, AT&T, and Verizon.

8. Dow Chemical and DuPont merger (2015) - $130B ($175.49B adjusted for inflation)

When Dow Chemical and DuPont announced they were merging in 2015, everyone sat up and took notice; the merger of equals would create the largest chemicals company by sales in the world, as well as eliminate the competition between them, making it a picture-perfect example of horizontal merger.

Shortly after the deal was completed, in 2018, the company was already generating revenue of $86B a year - but it didn’t last long: In 2019, management announced that the merged company would spin off into three separate companies, each with a separate focus.

9. United Technologies and Raytheon (2019) - $121B ($151.66B adjusted for inflation)

The merger between United Technologies Corporation (UTC) and Raytheon Company created Raytheon Technologies, an aerospace and defense giant. The new legal entity is expected to be the leader in aerospace and defense industries, with a broadened portfolio and enhanced market reach.

Now that the deal went through, Raytheon can leverage United Technologies' expertise in high temperature materials for jet engines; and in directed energy weapons, United Technologies has relevant power generation and management technology.

So far, however, investors seem less convinced with the company’s share price taking a dip of around 25% straight after the deal closed.

10. AB InBev and SABMiller merger (2015) - $107B  ($144.44B adjusted for inflation)

If stock price is any indication of whether a deal was successful or not, then the creation of AmBev through the merger of InBev and SABMiller in 2015 certainly wasn’t.

On paper, the deal looked good - two of the world’s biggest brewers bringing a host of the world’s favorite beers into one stable.

There was just one problem - they didn’t foresee the rise of craft beers and how it would disrupt the brewing industry. Several bolt-on acquisitions of craft brewers later and the new company may finally be on track again.

11. AT&T and Time Warner (2018) - $108B ($137.47B adjusted for inflation)

Not only did the proposed merger of AT&T and Time Warner draw criticism from antitrust regulators when it was announced, it also brought back memories of the previous time Time Warner had been involved in a megadeal.

With the best part of two decades to learn from its mistake, and AT&T a much bigger cash generator than AOL, this deal looks like it has been better thought through than the deal that preceded it.

12. Heinz and Kraft merger (2015) - $100B  ($135B adjusted for inflation)

The merger of Heinz and Kraft - to create the Kraft Heinz Company - is yet another megadeal that has a detrimental effect on stock.

The deal has been called a “mega-mess,” with billions knocked off the stock price since the deal closed. One of the reasons has been allegations made about accounting practices at the two firms before the merger.

Another reason has been zero-based budgeting (ZBB), a strict cost cutting regime that came at a time when old brands needed to be refreshed rather than have their budgets cut back.

13. BMO Financial Group and Bank of the West (2021) - $105B ($126.64B adjusted for inflation)

On December 20, 2021, BMO Financial Group announced the acquisition of BNP Paribas SA unit Bank of the West and its subsidiaries with assets worth approximately $105B. This merger is expected to significantly expand BMO’s presence in the U.S.

Through this acquisition, BMO can expand their customer base, increase their market presence in new regions, and enhance their existing capabilities with complementary products and services offered by Bank of the West.

14. Bristol-Myers Squibb and Celgene merger (2019) - $95B  ($119.07B adjusted for inflation)

Despite the massive size of the transaction, this 2019 megadeal wasn’t a “merger of equals.” Instead, Celgene became a subsidiary of Bristol-Myers Squibb. The deal brings together two of the world’s largest cancer drug manufacturers, so hopefully the deal amounts to something much greater than the sum of the parts.

15. Pfizer and Warner-Lambert (2000) - $90.27B ($168.72B adjusted for inflation)

In 2000, Pfizer acquired Warner-Lambert in a deal valued at more than $90B. This acquisition joined two of the fastest-growing companies in the pharma industry and created the second-largest pharmaceutical company in the world at the time, with a combined annual revenue exceeding $30B. It was one of the biggest pharmaceutical mergers at the time, significantly expanding Pfizer’s product portfolio and market presence. 

The deal provided Pfizer with full rights to Lipitor, a cholesterol-lowering medication that became the best-selling drug in the world in 2003, generating more than $13B in annual revenue at its peak. In addition, the deal helped to diversify Pfizer’s portfolio, adding other products such as Listerine mouthwash and Schick and Wilkinson Sword wet-shave products to its lineup.  

16. Energy Transfer Equity and Energy Transfer Partners (2018) - $90B  ($114.55B adjusted for inflation)

This deal is part of a strategic initiative to simplify Energy Transfer Equity’s corporate structure and streamlining their operations.​

Each ETP unit was converted into 1.28 ETE units, resulting in a major redistribution of shares but keeping the business essentially continuous under a new name. 

ETE was renamed Energy Transfer LP and began trading under the ticker symbol "ET" on the New York Stock Exchange. On the other hand, ETP was renamed Energy Transfer Operating L.P.

17. AT&T and BellSouth merger (2006) - $86B ($136.83 adjusted for inflation)

The merger of AT&T and BellSouth in 2006 for $86B was a pivotal event in the telecommunications sector, significantly reshaping the competitive landscape. The deal reunited two major components of what was previously an AT&T monopoly. The merger allowed AT&T to integrate BellSouth’s extensive wireline services with its own, enhancing its ability to offer bundled services like broadband, television, and wireless communications. 

The deal also gave AT&T complete control over BellSouth’s stake in Cingular Wireless, which was the nation’s largest mobile telephone provider at the time. Despite some scrutiny, the Federal Communications Commission (FCC) approved the deal after AT&T committed to maintaining network neutrality and freezing some wholesale rates for competitors. 

‍18. Unilever plc and Unilever N.V. (2020) - $81B  ($99.06B adjusted for inflation)

The M&A deal between Unilever plc and Unilever N.V. in 2020 was essentially a unification strategy. The primary goal was to create a more cohesive organization with streamlined operations and increased strategic flexibility. 

During this process, they made sure nothing will change in their operations, locations, activities or staffing levels in either The Netherlands or the United Kingdom.

17. Walt Disney and 21st Century Fox (2017) - $52.4B ($68.08B adjusted for inflation)

In December 2017, The Walt Disney Company acquired 21st Century Fox. Walt Disney’s goal was to boost their global presence and content diversity, adding to its strong franchise and streaming service portfolio. This acquisition enhanced Disney’s entertainment library and direct-to-consumer streaming offerings, bringing franchises like X-Men and Deadpool under one roof.

19. BHP Group Limited and BHP Group plc merger (2021) - $80.7B ($97.33B adjusted for inflation)

The BHP Group Limited and BHP Group plc merger, announced in 2021, unified BHP’s corporate structure under its existing Australian parent company, BHP Group Limited. The move was a strategic decision intended to simplify the company’s governance, reduce inefficiencies, and streamline its operations. 

The move was considered critical to positioning the company for long-term growth, particularly in sectors such as electrification and decarbonization. Following the unification, BHP retained listings on the Australian Stock Exchange (ASX), the London Stock Exchange (LSE), the Johannesburg Stock Exchange (JSE), and the New York Stock Exchange (NYSE), giving BHP global access to capital markets while simplifying its stock trading structure.  

Unifying the two entities also gave BHP flexibility to adjust its portfolio, better manage its investments, and pursue strategic initiatives in the evolving global economy. For instance, the merger was soon followed by another deal in 2022 that merged BHP Petroleum and Woodside Petroleum, creating a leading global energy company poised to play a significant role in the energy transition by leveraging Woodside’s expertise in clean energy solutions and also enabling BHP to invest in future-facing commodities needed for decarbonization. 

20. Exxon and Mobil merger (1999) - $80B ($153.62B adjusted for inflation)

The Exxon and Mobil merger in 1999 for $80B rejoined two of the biggest offshoots from John D. Rockefeller’s Standard Oil monopoly, which once controlled an estimated 90% of U.S. oil production but was dissolved in 1911 following a Supreme Court ruling.  

This merger created ExxonMobil, one of the world’s largest publicly traded energy corporations. The merger enabled the new entity to better navigate the global economy and maintain an edge in a sector with growing competition.

21. Linde AG and Praxair merger (2018) - $80B ($101.83B adjusted for inflation)

In 2018, Linde AG and Praxair completed a merger that formed the world’s largest industrial gas company at the time. The deal combined Linde’s engineering expertise with Praxair’s operational efficiency, resulting in a company with a market cap of $90B and more than 80,000 employees spanning over 100 countries. 

22. Royal Dutch Shell plc and Royal Dutch Shell N.V. merger (2021) - $71.5B ($86.24B adjusted for inflation)

In 2021, Royal Dutch Shell announced plans to unify its dual-share structure, which had been in place since 2005. The dual-share structure made decision-making and shareholder engagement complex, and the unification aimed to simplify its corporate governance. As part of this process, the company also changed its name to Shell plc. 

Unifying the two entities was also expected to reduce administrative costs associated with maintaining two separate share classes and the associated regulatory requirements.

23. CVS Health and Aetna merger (2018) - $70B ($89.1B adjusted for inflation)

The CVS Health and Aetna merger combined CVS’s extensive retail pharmacy network and pharmacy benefit management services with Aetna’s health insurance portfolio, creating a comprehensive healthcare model. The goal of the merger was to provide more coordinated care and make the consumer health experience more localized, less expensive, and more accessible, catering to the evolving needs of consumers.

24. Saudi Aramco and SABIC (2019) - $69.1B ($86.61B adjusted for inflation)

In 2019, Saudi Aramco entered an agreement to purchase a 70% stake in Saudi Basic Industries Corporation (SABIC). SABIC is one of the largest petrochemical companies in the world, providing Saudi Aramco with an extensive portfolio of chemicals, fertilizers, and plastics, enhancing Aramco’s ability to compete in the growing global chemicals market. 

SABIC’s strong presence in the global petrochemical market allowed Saudi Aramco to diversify its revenue sources. This reduces Saudi Aramco’s reliance on oil revenue, a strategic move to mitigate the risks associated with fluctuating oil prices.  

25. AbbVie and Allergan plc (2019) - $63B ($78.96B adjusted for inflation)

AbbVie’s acquisition of Allergan plc in 2019 for $63 billion expanded AbbVie’s portfolio, particularly in key therapeutic areas such as immunology, oncology, and neuroscience, adding drugs such as Botox, Juvederm, and Vraylar to its lineup. This also enabled AbbVie to reduce its reliance on Humira, its top-selling immunology drug, which was threatened by the emergence of similar drugs. 

This acquisition significantly increased AbbVie’s revenue to a combined base of around $50 billion in 2020. It also aligns with AbbVie’s strategy to diversify its revenue streams and strengthen its position for long-term growth in critical therapeutic markets.

26. Walt Disney and 21st Century Fox (2017) - $52.4B ($68.08B adjusted for inflation)

In December 2017, The Walt Disney Company acquired 21st Century Fox. Walt Disney’s goal was to boost their global presence and content diversity, adding to its strong franchise and streaming service portfolio. This acquisition enhanced Disney’s entertainment library and direct-to-consumer streaming offerings, bringing franchises like X-Men and Deadpool under one roof.

‍27. Bayer and Monsanto (2018) - $63B ($80.19B adjusted for inflation)

The deal between Bayer and Monsanto worth approximately $63B created one of the world's biggest agrochemical and agricultural biotechnology corporations. Bayer was known widely for its pharmaceutical division, but it also has a substantial crop science division, where they offer chemical and crop protection. 

Through the Monsanto acquisition, Bayer has strengthened their agricultural business using Monsanto’s expertise, which ultimately made them a global leader in seeds, traits, and agricultural chemicals.

After the completion of the deal in 2018, the integration has been complex due to the legacy issues inherited from the acquisition of Monsanto, such as culture, reputation, and legal and regulatory issues.

28. Microsoft and Activision Blizzard (2023) - $75.4B ($79.51B adjusted for inflation)

On January 18, 2022, Microsoft announced its intent to acquire Activision Blizzard, initially valued at $68.7B. The goal of this strategic acquisition was to significantly boost its gaming segment across various platforms including mobile, PC, console, and cloud. 

Microsoft can do this by integrating Activision Blizzard's strong portfolio of popular gaming franchises like Call of Duty, World of Warcraft, and Candy Crush. After overcoming numerous regulatory challenges, the deal was finalized on October 13, 2023. 

This acquisition, with the total cost amounting to $75.4 billion, represents one of the largest deals in the video game industry.

29. Broadcom and VMWare (2023) - $61B ($64.33B adjusted for inflation)

In November 2023, Broadcom acquired VMWare to strengthen its infrastructure software business by integrating VMWare’s extensive multi-cloud services capabilities. 

Due to the large scale of both companies’ operations, the deal had to go through a massive regulatory scrutiny and review. It involved multiple jurisdictions across the globe to assess its impact on competition and market dynamics within the tech industry.

30. Exxon Mobil and Pioneer Natural Resources (2023) - $59.5B ($62.75B adjusted for inflation)

As part of their strategy to enhance their production capabilities and market presence in the oil and gas industry, Exxon Mobil merged with Pioneer Natural Resources. 

They announced this deal in October 2023, with the goal to achieve a partnership that would combine their strengths in terms of resources and strengthen their portfolio in the global energy market. The deal closed in May 2024, creating “an Unconventional business with the largest, high-return development potential in the Permian Basin.” The combined company controls more than 1.4 million net acres in the Delaware and Midland basins with approximately 16 billion barrels of oil equivalent resource, according to an ExxonMobil press release.

31. S&P Global and IHS Markit (2020) - $44B ($53.81B adjusted for inflation)

S&P Global announced an all-stock merger with IHS Markit worth $44 billion in November 2020. Through this deal, S&P Global will gain access to a data provider that supplies financial information to 50,000 customers across business and governments. Both companies expected a generated annual free cash flow of exceeding $5bn by 2023.

32. Discovery, Inc. and WarnerMedia (2022) - $43B ($48.25B adjusted for inflation)

On April 8, 2022, Discovery Inc. and WarnerMedia finalized a merger that would enhance their global media and entertainment footprint. The goal was to combine Warnermedia’s extensive entertainment assets with Discovery's non-fiction and international entertainment.

This $43B deal formed a new entity called Warner Bros. Discovery, which now has a vast portfolio that includes networks such as CNN, HBO, and Discovery Channel, as well as streaming services like HBO Max and Discovery+.

This horizontal merger boosted the newly formed company to compete with other major players like Netflix and Disney+ by providing a richer diversity of content across genres.

33. Pfizer and Seagen (2023) - $43B ($45.35B adjusted for inflation)

Pfizer’s acquisition of Seagen for $43B in March 2023 marked one of the largest deals in the biopharmaceutical sector since 2019.

Since Seagen is a biotech company known for its expertise in developing antibody-drug conjugates (ADCs) and other innovative cancer therapies, this acquisition will strengthen Pfizer’s oncology portfolio and expand their presence in the cancer treatment market.

34. Elon Musk and Twitter, Inc. (2022) - $44B (49.38B adjusted for inflation)

One of the most widely discussed acquisitions in the tech industry, Elon Musk’s 2022 acquisition of Twitter for $44 billion didn’t go smoothly, to say the least. After initially expressing interest in purchasing the social media platform in April 2022, Musk started having second thoughts and attempted to back out of the deal in July of the same year. 

However, Twitter’s board then responded by threatening legal action to enforce the original agreement. Eventually, Musk proceeded with the acquisition, but the process was further complicated because Twitter’s value had fluctuated during the course of negotiations, and Musk also had to navigate regulatory approval processes. 

After the deal closed, Musk made significant changes, rebranding the company as X in 2023 and restructuring the company’s internal operations. This included a substantial reduction in the company’s workforce, and the sudden shifts in company culture and management style led to instability during the transition period.   

Initially, many analysts criticized the deal and believed that Twitter was overpriced. However, two years later, things have changed. Twitter, now X, has become a critical data source for Musk’s AI startup, xAI, which has rapidly grown to a $50 billion valuation. Musk’s ownership of X has also provided him with significant political influence, and he played a prominent role in the 2024 U.S. election.

35. Altimeter and Grab Holdings (2021) - $40B ($48.24B adjusted for inflation)

Altimeter’s stock-for-stock merger with Grab Holdings marked as the largest de-SPAC transaction at that time, worth approximately $40B. 

Instead of a traditional IPO process, Altimeter helped Grab go public through a reverse merger. The primary motive of the deal was to boost Grab's dominance in Southeast Asia by providing them with additional capital to propel their expansion and face their fierce competition, particularly Gojek.

It's a win-win move for Altimeter because the merger carved an opportunity for them to invest in a fast-growing tech company with a solid market presence in a rapidly developing region.

Exxon Mobil and Pioneer Natural Resources (2023) - $59.5B ($62.75B adjusted for inflation)

This is a great example of a merger of equals where no payment was made from one company to another. This was an all-stock transaction, where Pioneer shareholders will receive 2.3234 shares of ExxonMobil for each Pioneer share at closing.

United Technologies and Raytheon (2019) - $121B ($151.66B adjusted for inflation)

Another classic example of a so-called “merger of equals.” The United Technologies and Raytheon merger is also an all-stock transaction, where Raytheon shareholders receive shares in the new company, while UTC shareholders maintain a majority stake.

Discovery, Inc. and WarnerMedia (2022) - $43B ($48.25B adjusted for inflation)

Despite the first two examples mentioned above, not all mergers involve two equal-sized companies. When AT&T owned WarnerMedia, they merged it with a smaller company, Discovery Inc. This special kind of deal is called a Reverse Morris Trust. So even though it's a merger, AT&T got $40.4 billion in cash as a payment. 

This payment was part of the deal to help balance things out between what AT&T was giving up and what they were getting in return. AT&T shareholders also ended up owning a big part of the combined company.

‍Amazon and Whole Foods (2017) - $13.7B ($17.8B adjusted for inflation)

Though this deal did not make our top 25, it’s certainly a great example of a successful acquisition. Amazon bought Whole Foods in 2017 for approximately $13.7B to have greater control of their supply chain and broaden their reach into new markets. 

Before this deal, Amazon was more focused on e-commerce. This strategic move allowed them to expand into the brick-and-mortar grocery sector, through Whole Foods. Amazon was able to integrate its e-commerce capabilities with Whole Foods' physical store network and achieved economies of scale in several areas, especially in distribution and logistics.

Lessons from successful and failed mergers and acquisitions 

Whether it’s a success or failure, there are always lessons to be learned in the world of mergers & acquisitions. Here are some of the best lessons we want to emphasize and share.

Don’t overlook culture 

In the past, culture was one of the most underrated aspects of M&A. No one cared about it, and deal makers were only focused on the numbers and synergies. Today, practitioners are catching on, and they tend to focus more on culture during due diligence. But for those who are still not believers, you can always look up the Daimler Benz and Chrysler deal back on May 7, 1998. 

Daimler was aggressive during integration and Chrysler didn’t want to be told what to do. They didn’t get along and continued to run as separate operations. The entire deal was a disaster, which eventually led to Daimler Benz selling Chrysler to the Cerberus Capital Management firm.

Don’t take due diligence for granted

M&A teams must never take due diligence for granted and turn every possible stone. One mistake can cause massive headaches, and potentially destroy the acquiring company.  HP learned this the hard way when they acquired Autonomy back in 2011. The plan was to transform HP from a computer and printer maker into a software-focused enterprise services firm. 

The problem came after the deal was closed, and HP discovered that Autonomy was cooking the books by selling hardware at a loss to its customers while booking the sales as software licensing revenue. This is one of the most controversial deals of all time, generating massive lawsuits due to fraudulent accounting practices.

Plan for integration early in the process

The biggest mistake any practitioner could make is not planning for integration early in the M&A process. Integration is where value is created, and must be prioritized during due diligence. 

The Sprint and Nextel Communications deal back in 2005 is a great example of the importance of integration planning. The combination of these two legal entities created the third largest telecommunications provider at that time. The goal is to gain access to each other's customer bases and cross sell their product lines. 

However, due to the lack of integration planning during the diligence they were not prepared for what was about to come after closing. Apparently the two companies' networks did not share the same technology and had zero overlap making integration extremely difficult. They also lost a significant amount of market share due to their clashing marketing strategies that allowed rivals to steal dissatisfied customers.

Emerging trends in mergers and acquisitions

According to Deloitte’s 2024 M&A Trends Survey (conducted in early 2024), 79% of corporate leaders and 86% of private equity leaders said they expect an increase in deal volume over the next 12 months, and 99% of respondents indicated that their corporate or private equity organizations are incorporating generative AI or advanced data analytics into their M&A processes. 

Many factors can impact M&A activity. Here’s a look at some current and emerging trends that are driving mergers and acquisitions as we enter 2025.  

Economic uncertainty 

Many companies are reevaluating their portfolios due to geopolitical tensions and a fluctuating global economy. Some companies are opting to divest their non-essential assets in order to focus on their core competencies.

68% of corporate leaders surveyed by Deloitte said their companies had restructured since the COVID-19 pandemic, while 27% are currently restructuring or planning to do so within the next six months. 

The consumer health sector, which is currently valued at $356 billion, has had some fluctuations in recent years. Companies that sell everyday health products, like toothpaste and over-the-counter pain relievers, used to be part of the portfolios of big pharmaceutical companies. However, as pharmaceutical giants’ biggest products had expiring patents, they needed resources to invest in drug research and development. So, many of these pharmaceutical companies sold the consumer health components of their businesses. 

For example, a company called Haleon was created through a merger of GlaxoSmithKline’s (GSK) and Pfizer’s consumer healthcare businesses in 2019, with both GSK and Pfizer retaining stakes in the company. GSK sold off its Haleon holdings in a series of transactions in 2023 and 2024, raising $1.52 billion from the final sale of its remaining shares in May 2024. 

Johnson & Johnson also demerged its consumer healthcare business in May 2023 as Kenvue, and Sanofi announced plans to sell 50% of its consumer health company, Opella, in October 2024, with Bayer reportedly considering a similar move. Now, some of these smaller spinoffs are in merger talks with the goal of consolidating market share, so an increase in M&A activity is expected to consolidate and reshape the consumer healthcare sector.

Check out the video below for insights from Jerome Combes-Knoke, Senior Vice President of Strategy and Corporate Development at Dotmatics (a portfolio company of Insight Partners), on his approach to portfolio strategy and rebalancing through divestitures:

Technological advancements

Rapid advancements in technology make it necessary for companies to restructure to integrate new technologies and business models — in some cases, it’s essential for survival. Companies are consolidating their resources to enhance capabilities in areas like artificial intelligence and data analytics. 

For example, the pending $13.25 billion merger between Omnicom and Interpublic Group (IPG) — the world’s third- and fourth-largest ad buyers — would create a company with revenue exceeding $25 billion. The deal, which is expected to close in the second half of 2025, would make Omnicom the largest agency holding company and would enhance capabilities in areas such as AI, data, and media buying.  

In the financial sector, banks and other financial institutions are looking to acquire fintech startups to stay on track with digital transformation. For example, SoFi acquired core banking platform Technisys for $1.1 billion in 2022. This acquisition allows SoFi to leverage Technisys’ technology, which supports mobile banking apps and tracks deposits, to deliver personalized banking services to its customers. 

Another example in the financial services sector is Truist Financial’s acquisition of Long Game in 2022. Long Game is a fintech startup that offers a gamified mobile finance app, so the acquisition allows Truist Financial to attract younger demographics and innovate its digital offerings. 

Regulatory changes

The anticipated return of President-elect Donald J. Trump to the White House in 2025 is expected to create a more favorable M&A landscape. His pro-business stance and potential relaxation of antitrust regulations are likely to encourage deal-making, with Goldman Sachs predicting a 20% increase in M&A activity in 2025. 

Increased focus on solid M&A strategy and deal valuation

The top factors that drive the success of M&A deals, according to Deloitte’s survey, are defining “a coherent and well-supported M&A strategy,” followed by an emphasis on deal valuation. 

Companies are aligning their strategic objectives to drive growth and enhance their competitive position in the market. A well-defined M&A strategy helps companies ensure that their acquisitions will complement their existing operations and contribute to the company’s long-term goals. 

For instance, AbbVie, a pharmaceutical company, has been steadily growing its pharmaceutical pipeline through acquisitions. In February 2024, AbbVie acquired ImmunoGen, adding a flagship product, ELAHERE® (mirvetuximab soravtansine-gynx), which treats folate receptor-alpha (FRα) positive platinum-resistant ovarian cancer (PROC), to its portfolio. 

AbbVie is also set to acquire Aliada Therapeutics, which will allow AbbVie to utilize Aliada's blood-brain barrier (BBB)-crossing technology to enhance its development efforts in the field of neuroscience.  

Accurate deal valuation is vital in M&A transactions, as it influences the outcome of negotiations and can also have a significant impact on integration when the deal closes. Leveraging appropriate valuation methods, such as market-based, income-based, and asset-based valuation approaches, can help companies determine a fair purchase price and identify potential synergies. 

For example, Blackstone is set to acquire AirTrunk, the largest data center platform in the Asia Pacific region, for $24B. AirTrunk has 800MW of capacity committed to customers and also owns land that can support future growth in the region of more than 1GW. The $24B valuation reflects the current value of AirTrunk’s assets, customer base, and growth potential, and this deal aligns with Blackstone’s goal to become the leading digital infrastructure investor in the world.  

International targeting

As the world becomes increasingly interconnected, companies are looking to expand their presence globally to tap into new customer bases and diversify their revenue streams. In fact, according to Deloitte, there’s been a 22% increase in international targeting to find value between 2022 and 2024. 

When domestic markets are saturated, developing economies can offer growth opportunities. Acquiring businesses in foreign markets allows companies to leverage local market knowledge and distribution networks to accelerate their entry and growth in the region. 

For example, Uber Eats has reached an agreement with Delivery Hero to acquire its foodpanda business in Taiwan for $959 million. Uber has an existing presence in Taiwan, but this acquisition will allow the company to leverage foodpanda’s coverage in Taiwan and the relationships it has built with local brands. 

Frequently asked questions

What is the main purpose of mergers and acquisitions? 

The main purpose of mergers and acquisitions is to increase a company’s market share, expand its product offerings, achieve cost efficiencies, or access new markets and resources. M&A can also be driven by the desire to improve competitiveness or create value for shareholders. 

Is an acquisition a takeover?

A takeover is a specific type of acquisition. An acquisition is typically an amicable transaction, with both parties in agreement. When a buyer purchases shares from shareholders or makes an offer to the shareholders without the target company’s approval, it’s considered a takeover. 

What’s the biggest concern people have about mergers? 

Companies often streamline their operations following a merger. If redundancies are found, positions may be eliminated, so many people are concerned about potential job loss. Culture conflicts, integration challenges, and decreased employee morale are also among the top concerns people have related to mergers. 

What happens when two companies merge? 

When two companies merge, they combine their assets, operations, and resources into a single entity. This often includes restructuring, rebranding, and aligning company culture to increase the company’s strength in the market and boost profitability. 

What is the merger paradox? 

The merger paradox relates to unrealized expectations. Mergers always come with anticipated benefits, such as increased efficiency and market share, but these expectations are not always realized. Instead, mergers can sometimes result in operational inefficiencies, conflicts, or even diminished value. 

What are two motives behind mergers and acquisitions? 

One of the most common motives behind mergers and acquisitions is to create a combined company that is more valuable than the value of the two companies before the merger or acquisition (greater than the sum of its parts). Mergers and acquisitions are also motivated by market expansion opportunities, which allow a company to enter new geographic regions or product markets quickly.

Final thoughts

Overall, it’s hard to argue which deal in US history is the most successful merger or acquisition due to the fact that sometimes the full value and potential of a deal takes years to formulate.

However, the top mergers and acquisitions (like some of those that are currently upcoming M&A deals for 2025) take into account best practices such as robust communication, focus on the strategic goal/deal thesis, and early integration planning throughout the deal lifecycle.

Much can be learned from companies that have successfully merged with or acquired other companies.

The right technology and tools can also work to make deals more successful.

‍The DealRoom M&A Platform aims to help teams manage their complex M&A transactions. The DealRoom M&A Platform is a purpose-built, unified solution designed to streamline every stage of the M&A lifecycle. From deal pipeline management to due diligence to post-merger integration(PMI), DealRoom provides the tools and features corporate development teams need to optimize their processes, eliminate inefficiencies, and achieve better outcomes.