The 30 Largest Mergers in History That Has Reshaped Global Business

Last Updated on May 1, 2025

Big companies don’t always grow by playing nice. Sometimes, they join forces. Other times, one swallows the other. Either way, the result can reshape entire industries.

This article covers the 30 largest mergers in history, deals that changed how we communicate, what we eat, how we bank, and even how we get healthcare. Some were smart. Others? Not so much. But all of them came with big promises, huge risks, and plenty of attention from investment banks, shareholders, and regulators.

You’ll see mergers and acquisitions from the pharmaceutical industry, the oil and gas industry, tech, finance, telecom, and more. From the Exxon and Mobil merger to the rise of the Kraft Heinz Company, every deal here left a mark.

These weren’t just boardroom conversations, they were global events. And in today’s high-stakes corporate world, deals like these rely heavily on secure tools like Virtual Data Rooms to manage sensitive documents, streamline the acquisition process, and reduce integration challenges.

Let’s get into the numbers and the names that made M&A history.

1. Vodafone Acquires Mannesmann – $180.95 Billion

Industry: Telecom
Deal Type: Acquisition

This is still one of the largest merger in corporate history. In 1999, Vodafone launched a hostile takeover of Germany’s Mannesmann to grow its grip on the mobile market. The deal valued at $180.95 billion shocked Europe and pushed the limits of what was possible in mergers and acquisitions.

The acquiring company faced fierce resistance, but pressure from the target company’s shareholders made the deal happen. The result? A newly formed company that briefly ruled as the third largest telecommunications provider worldwide.

It wasn’t a perfect fit. Integration challenges between the two companies slowed things down. But the size and boldness of this mega deal changed the game.

2. AOL Merges with Time Warner – $162 Billion

Industry: Media & Internet
Deal Type: Merger

The AOL and Time Warner merger in 2000 was meant to be a match made in media heaven. The deal valued at $162 billion combined a rising internet star with a traditional media powerhouse. On paper, it looked like a strategic move toward dominating the digital future.

But the timing was off. The dot-com bubble popped, and the newly formed company struggled from day one. The two companies had clashing corporate cultures, and synergy never materialized.

It’s now often called one of the biggest mergers, and one of the costliest failures, in corporate history. A reminder that not all mega deals deliver shareholder value, even with help from the best deal makers and investment banks.

3. Dow Merges with DuPont – $130 Billion

Industry: Chemicals
Deal Type: Merger

This proposed merger between Dow and DuPont in 2015 created a new company with a combined market cap of around $130 billion. It wasn’t just about size, the goal was strategic alignment, cutting overlap, and unlocking massive cost savings.

Once merged, the newly formed company split into three separate companies, each focused on agriculture, materials science, and specialty products. This plan made the complex integration process a bit more manageable.

The Dow-DuPont merger quickly became one of the most talked-about deals in the chemical sector, with deep involvement from investment banks, regulators, and antitrust watchdogs. It showed how mergers and acquisitions can reshape entire industries when there’s a clear plan for market expansion and breaking up later.

4. United Technologies Merges with Raytheon – $121 Billion

Industry: Aerospace & Defense
Deal Type: Merger

In 2019, United Technologies Corporation and Raytheon agreed to a strategic merger to form an aerospace powerhouse. The deal valued at $121 billion combined commercial aviation with defense tech, creating a new entity: Raytheon Technologies.

This merger allowed both sides to diversify. Raytheon brought in radar and missile systems. United Technologies contributed engines and avionics. Together, they formed a global leader in aerospace systems with serious production capabilities and a massive combined annual revenue.

The merger wasn’t just about size. It was a push to stay competitive in a tight corporate world, especially with rising global defense spending and pressure to deliver more innovation.

5. AT&T Acquires Time Warner – $108.7 Billion

Industry: Media & Telecommunications
Deal Type: Acquisition

When AT&T bought Time Warner in 2016 for $108.7 billion, it marked a bold strategic move to blend content with distribution. The acquiring company wanted full control, not just over mobile networks, but over what people watched on them.

The target company owned huge media brands like HBO, CNN, and Warner Bros. AT&T’s plan was to stack content, data, and delivery into one seamless experience. A vertical integration play.

But this mega deal wasn’t smooth. Regulators delayed it, worried about market share issues. Post-merger, the new company faced tough competition from streaming giants.

Still, the deal changed the telecommunications industry, proving how far one company would go to stay relevant in a changing business environment.

6. AB InBev Acquires SABMiller – $107 Billion

Industry: Beverage
Deal Type: Acquisition

In 2015, AB InBev went after its biggest rival, SABMiller, in a deal valued at $107 billion. It was a move to dominate the global beer market and cement its place among the largest corporate mergers ever.

This wasn’t just about expanding shelf space. The acquiring company wanted local market knowledge, especially in Africa and Latin America where SABMiller was strong. The merger allowed AB InBev to become the fifth largest food company by revenue at the time.

To get it approved, they had to sell off key brands, a classic acquisition process challenge. Even so, the resulting combined company had an enormous footprint, with operations in over 100 countries.

It was a clear play for market expansion, even if it meant navigating a maze of regulators and complex corporate governance.

7. Glaxo Wellcome Merges with SmithKline Beecham – $107 Billion

Industry: Pharmaceuticals
Deal Type: Merger

In 2000, two major pharmaceutical companies, Glaxo Wellcome and SmithKline Beecham, joined forces in a merger valued at $107 billion. The goal? To become a global leader in drug development and strengthen their pipeline across key therapeutic areas.

The new company, GlaxoSmithKline, instantly became one of the largest players in the pharmaceutical industry. But the deal came with the usual integration challenges, overlapping operations, regulatory hurdles, and big decisions on leadership.

Still, this merger allowed the firms to scale R&D and better compete with rising biotech startups.

8. Exxon Merges with Mobil – $81 Billion

Industry: Oil & Gas
Deal Type: Merger

The Exxon and Mobil merger in 1998 created ExxonMobil, a titan in the oil and gas industry. The deal valued at $81 billion wasn’t just about survival; it was a strategic move during a downturn in oil prices.

These weren’t just any two firms, they were direct descendants of Rockefeller’s Standard Oil. So this wasn’t just another merger; it was a piece of corporate history coming full circle.

The newly formed company brought together massive production capabilities, cut costs, and solidified its place among the largest mergers in history. It’s also one of the clearest examples of a successful merger in the energy sector.

9. Royal Dutch Petroleum Merges with Shell Transport & Trading – $74.5 Billion

Industry: Oil & Gas
Deal Type: Merger

In 2004, Royal Dutch Petroleum and Shell Transport & Trading merged to create Royal Dutch Shell, in a deal valued at $74.5 billion. Before that, the two companies operated as separate companies under a dual-ownership structure.

This merger allowed them to streamline governance, simplify decision-making, and boost investor confidence. The result? A new entity better positioned to navigate global markets and improve capital efficiency.

It was also a key moment in the gas industry, showing how legacy firms had to evolve or risk falling behind.

10. Pfizer Acquires Wyeth – $68 Billion

Industry: Pharmaceuticals
Deal Type: Acquisition

In 2009, Pfizer acquired Wyeth in a deal valued at $68 billion, aiming to boost its vaccine and biotech portfolio. The move came just after Pfizer acquired Warner Lambert, making this part of a bigger push to dominate the pharmaceutical industry.

The acquiring company needed new revenue streams, and Wyeth’s strength in biologics made the deal attractive. With this successful merger, Pfizer gained ground in areas where it was previously weak.

It also helped reduce reliance on blockbuster drugs nearing patent expiry, a big concern in pharma during that time.

11. Dell Acquires EMC – $67 Billion

Industry: Technology
Deal Type: Acquisition

This 2016 deal between computer and printer maker Dell and storage giant EMC reshaped enterprise tech. The deal valued at $67 billion became one of the biggest acquisitions ever in the tech space.

Dell, the acquiring company, wanted more software licensing revenue and deeper reach into cloud infrastructure. EMC brought that, along with its stake in VMware.

The resulting combined company offered end-to-end IT solutions, from servers to cloud software. Integration was tricky, but it gave Dell more control over the enterprise ecosystem.

12. Walt Disney Company Acquires 21st Century Fox – $71.3 Billion

Industry: Entertainment
Deal Type: Acquisition

In 2019, the Walt Disney Company acquired most of 21st Century Fox’s assets in a deal valued at $71.3 billion. It was a massive content grab in the middle of the streaming wars.

The acquiring company picked up studios, regional sports networks, and international assets. This strategic move strengthened Disney+, putting it in direct competition with Netflix and Amazon.

The new company gained a library of franchises, from X-Men to Avatar, plus market expansion into new territories. For Disney, this was about staying a market leader in a fast-changing business environment.

13. Heinz Merges with Kraft – $63 Billion

Industry: Food & Beverage
Deal Type: Merger

In 2015, Kraft and Heinz combined forces in a merger valued at $63 billion. The goal? To form the Kraft Heinz Company, one of the fifth largest food companies in the world by revenue.

Backed by 3G Capital and Warren Buffett’s Berkshire Hathaway, the newly formed company looked great on paper, global brands, big savings, and massive reach.

But soon after, cracks showed. Slowed growth, shifting consumer tastes, and internal integration challenges made it tough to keep momentum. Still, it remains one of the largest mergers in the food industry to date.

14. Actavis Acquires Allergan – $66 Billion

Industry: Pharmaceuticals
Deal Type: Acquisition

This mega deal happened in 2014, when Actavis, a fast-growing pharma firm, acquired Allergan in a $66 billion transaction. The acquiring company wanted to grow fast and take on bigger players in the pharmaceutical industry.

The move came just after Allergan fended off a hostile takeover by Valeant. Actavis swooped in with a friendlier offer and closed quickly.

After the deal, Actavis took on the target company’s name, rebranding as Allergan. It’s a classic example of a strategic move done right, with fast execution and long-term growth in mind.

15. CVS Health Acquires Aetna – $69 Billion

Industry: Healthcare & Insurance
Deal Type: Acquisition

In 2017, CVS Health made headlines when it acquired insurance giant Aetna in a deal valued at $69 billion. The idea was to merge pharmacy, retail, and insurance into a single, efficient new entity.

The acquiring company wanted to control more of the healthcare journey, from treatment to payment. And with rising costs in the U.S., this kind of vertical integration looked like the future.

It also promised cost savings, better coordination, and more convenience for patients. The deal reshaped what a modern healthcare company could look like.

16. Bristol-Myers Squibb Acquires Celgene – $74 Billion

Industry: Pharmaceuticals
Deal Type: Acquisition

In 2019, Bristol-Myers Squibb made a bold strategic move by acquiring Celgene in a deal valued at $74 billion. This gave them a strong cancer and immunology portfolio, boosting their edge in the pharmaceutical industry.

The acquiring company aimed for market expansion and more firepower in biotech. The deal was risky, big price tag, complex pipelines, but the potential rewards made it worth it.

Celgene’s shareholders got a mix of cash and stock, plus rights to future drug approvals. It’s one of the largest mergers in history for pharma.

17. Takeda Acquires Shire – $62 Billion

Industry: Pharmaceuticals
Deal Type: Acquisition

In 2018, Japan’s Takeda bought Ireland-based Shire in a $62 billion deal, marking the largest overseas acquisition by a Japanese company.

The target company had strong assets in rare diseases, something Takeda wanted badly. This merger allowed them to become a global leader in specialty care, even if it meant taking on debt.

Cultural and operational integration challenges were expected. Still, this deal showed how pharmaceutical companies chase growth far beyond their borders.

18. Glencore Merges with Xstrata – $62 Billion

Industry: Mining & Commodities
Deal Type: Merger

In 2012, Glencore and Xstrata joined forces in a merger valued at $62 billion. The result? One of the biggest resource companies on the planet.

Both firms were already giants in commodities. The newly formed company hoped to cut costs and boost negotiating power in volatile capital markets.

This deal wasn’t smooth, though. Shareholder pushback and executive pay debates nearly derailed it. But it eventually went through, adding another name to the list of largest corporate mergers.

19. Verizon Buys Vodafone’s Stake in Verizon Wireless – $130 Billion

Industry: Telecommunications
Deal Type: Acquisition

In 2013, Verizon bought back Vodafone’s 45% stake in Verizon Wireless for $130 billion, making it one of the biggest acquisitions in the telecommunications industry.

This wasn’t a full merger, but the acquiring company finally gained complete control of its wireless business, something it had been eyeing for years. The deal simplified ownership and eliminated friction between the two companies.

It also gave Verizon more flexibility in strategy, operations, and tech investments, all key in a fast-moving mobile market.

20. Charter Communications Acquires Time Warner Cable – $78.7 Billion

Industry: Telecommunications
Deal Type: Acquisition

In 2015, Charter Communications scooped up Time Warner Cable in a deal valued at $78.7 billion. The goal? To become a serious rival to Comcast in the U.S. cable space.

The acquiring company also bought Bright House Networks around the same time. These deals combined to create the third largest telecommunications provider in the country.

The merged company promised faster broadband, better customer service, and nationwide reach. It was a classic market expansion play, powered by scale and better infrastructure.

21. Cigna Acquires Express Scripts – $67 Billion

Industry: Healthcare
Deal Type: Acquisition

In 2018, Cigna paid $67 billion to buy Express Scripts, a pharmacy benefits manager. The deal aimed to bring together insurance, data, and prescription services in one tight system.

It’s one of those mega deals focused on vertical integration, not just size. The acquiring company wanted to lower costs, improve outcomes, and take control of more parts of the healthcare chain.

This strategic alignment shifted how the industry thought about insurer–provider relationships.

22. Saudi Aramco Acquires SABIC Stake – $69.1 Billion

Industry: Petrochemicals
Deal Type: Acquisition

In 2019, Saudi Aramco bought a 70% stake in SABIC from Saudi Arabia’s Public Investment Fund for $69.1 billion. It was a huge consolidation in the country’s oil and gas industry.

The acquiring company, already a global energy giant, used this strategic move to diversify beyond crude. SABIC’s chemicals expertise gave Aramco access to new products and market expansion opportunities.

This merger allowed the Saudi government to shift assets internally while raising cash for other investments, a clear play in long-term corporate governance planning.

23. Sanofi Acquires Genzyme – $20.1 Billion

Industry: Pharmaceuticals
Deal Type: Acquisition

In 2011, French pharma company Sanofi acquired U.S.-based Genzyme in a deal valued at $20.1 billion. The target? Genzyme’s strong pipeline in rare diseases.

This acquisition process wasn’t fast. Negotiations dragged out as the target company pushed for more value. Eventually, a deal with milestone-based payouts sealed it.

The move helped Sanofi build its rare disease portfolio and reinforced its presence in the U.S., a textbook case of market expansion through smart M&A.

24. J.P. Morgan Merges with Chase Manhattan – $30.9 Billion

Industry: Financial Services
Deal Type: Merger

In 2000, J.P. Morgan & Co. merged with Chase Manhattan Bank to form what we now know as JPMorgan Chase, one of the biggest banks in the world.

The deal valued at $30.9 billion was a response to pressure from global capital markets and rising competition from other merged companies.

By combining investment banking strength with a huge retail base, the new entity became a force across nearly every area of finance, and a central figure in modern corporate history.

25. Bank of America Acquires Merrill Lynch – $50 Billion

Industry: Financial Services
Deal Type: Acquisition

In the heat of the 2008 financial crisis, Bank of America stepped in to acquire Merrill Lynch for $50 billion. It was a rushed but critical strategic move to stabilize the banking system.

The acquiring company got Merrill’s investment banking and wealth management units, while Merrill got saved from collapse. It’s now seen as a rare successful merger from a chaotic time.

Still, there were integration challenges, culture clashes and risky assets. But the merged company survived, and even thrived, as markets recovered.

26. AOL Acquires Netscape – $4.2 Billion

Industry: Technology
Deal Type: Acquisition

In 1998, America Online bought Netscape for $4.2 billion, trying to dominate both internet access and the browser market.

It didn’t work. Microsoft’s Internet Explorer crushed Netscape, and AOL’s relevance faded over time. Even with the hype, this one didn’t deliver long-term shareholder value.

Still, it’s part of corporate history, a reminder that not all mergers succeed, no matter how bold the vision.

27. Facebook Acquires WhatsApp – $19 Billion

Industry: Technology
Deal Type: Acquisition

In 2014, Facebook paid $19 billion for WhatsApp, one of the biggest tech deals ever at the time, especially considering WhatsApp’s limited revenue.

The acquiring company wanted to own messaging. With this deal, it captured over 400 million users in one shot. A move that also helped it steal dissatisfied customers from competitors in the mobile market.

Data, reach, and scale, that’s what this strategic alignment was all about.

28. Microsoft Acquires LinkedIn – $26.2 Billion

Industry: Technology / Social Media
Deal Type: Acquisition

In 2016, Microsoft acquired LinkedIn for $26.2 billion in one of its most strategic moves since acquiring Skype.

The goal? Blend professional networking with Microsoft’s suite of business tools. This deal helped drive software licensing revenue and gave the acquiring company rich user data across the corporate world.

Despite early doubts, the integration worked. LinkedIn remained semi-autonomous and kept growing, making this one of Microsoft’s cleanest mega deals to date.

29. Chevron Acquires Hess Corporation – $53 Billion (Pending Completion)

Industry: Oil & Gas
Deal Type: Acquisition

Announced in 2023, Chevron plans to acquire Hess Corporation for $53 billion. The move aims to expand Chevron’s deepwater oil portfolio, especially in Guyana.

The acquiring company expects long-term cost savings and more stable output in a volatile gas industry. The deal is still under review, but if it closes, it’ll mark another huge shift among market leaders in the oil and gas industry.

30. Broadcom Acquires VMware – $61 Billion

Industry: Technology
Deal Type: Acquisition

In 2022, Broadcom announced its acquisition of VMware for $69 billion, aiming to beef up its software offerings and reduce reliance on chips.

This strategic move gave Broadcom a big piece of the software licensing revenue pie. VMware’s cloud infrastructure tools fit neatly into Broadcom’s enterprise focus.

The combined company is now a heavyweight in hybrid cloud, and this is one of the largest mergers in history in the tech sector.

Companies	Value ($B)	Industry
Vodafone / Mannesmann	202.8	Telecom
AOL / Time Warner	164.7	Media & Internet
Dow / DuPont	130.0	Chemicals
Verizon / Vodafone Stake	130.0	Telecom
United Technologies / Raytheon	121.0	Aerospace & Defense

Conclusion

So, what can you take from all this?

Some of these mega deals made headlines for record-breaking transaction values. Others became cautionary tales. But every one of them changed the course of the companies involved, and often, the markets around them.

Whether it was the merger created ExxonMobil, the failed dreams of America Online and Time Warner, or Pfizer acquiring Warner Lambert and Wyeth to dominate pharma, these weren’t just transactions. They were inflection points in corporate history.

Behind each of these moves were tough decisions, complex due diligence, and layers of red tape. And in many cases, tools like Virtual Data Rooms helped the acquiring company and the target company keep things secure, efficient, and under control.

The largest corporate mergers teach us that success isn’t guaranteed, even when the numbers look good. But when the timing, strategy, and execution line up, the results can turn two giants into one global leader.