M&A (mergers and acquisitions) refers to the process where one company either combines with another company (merger) or purchases it (acquisition). Many mergers and acquisitions examples prove that these business transactions can increase market presence, reduce competition, and improve financial performance.
In this article, we’ll explore the biggest acquisitions of all time and learn several lessons from them, like how to maximize value, manage integration challenges, and achieve strategic objectives.
15 examples of the biggest mergers and acquisitions of all time
Here is a list and description of historic M&A deals with details on their purposes and outcomes:
- America Online (AOL) and Time Warner: $350 billion
- China Shenhua Group and China Guodian Corporation: $278 billion
- ChemChina and Sinochem: $245 billion
- United Technologies and Raytheon: $121 billion
- Dow Chemical and DuPont: $130 billion
- Pfizer and Warner-Lambert: $90.27 billion
- Microsoft and Activision Blizzard: $75 billion
- Walt Disney Company and 21st Century Fox: $71.3 billion
- ExxonMobil and Pioneer Natural Resources: $60 billion
- H.J. Heinz Co. and Kraft Foods Group: $45 billion
- Liberty Global and Telefónica: $38.9 billion
- Sprint and Nextel Communications: $35 billion
- Energy Transfer Equity (ETE) and Energy Transfer Partners (ETP): $27 billion
- London Stock Exchange and Refinitiv: $27 billion
- HP and Autonomy: $11.7 billion
1. America Online (AOL) and Time Warner
Year: 2000
Deal value: $350 billion
This deal is notable for being the largest merger and acquisition deal in history at the time, with a transaction value of $360 billion. It combined AOL’s extensive internet subscriber base with Time Warner’s vast media assets. Under the terms, AOL shareholders were to own 55% of the new legal entity.
The acquisition was initially regarded as a strategic powerhouse, merging the world’s largest internet provider with a leading media conglomerate. However, the deal soon encountered severe challenges. The economic downturn and the burst of the dot-com bubble significantly devalued the merged company. As broadband technology advanced, AOL’s dial-up service quickly became outdated, worsening the company’s problems.
By 2002, AOL Time Warner reported a staggering $98.7 billion loss, the largest annual loss in corporate history at that time. This decline led to widespread financial losses for shareholders and employees, with some estimates suggesting that figures like Ted Turner lost billions due to the merger.
In 2009, Time Warner separated AOL into an independent entity, and by 2015, Verizon acquired AOL for $4.4 billion. The deal remains one of the worst mergers in history.
2. China Shenhua Group and China Guodian Corporation
Year: 2017
Deal value: $278 billion
In August 2017, the Chinese government approved the merger of China Shenhua Group and China Guodian Corporation, marking it one of the biggest mergers in history. This consolidation created the largest power company in the world, known as State Energy Investment Group.
The merger aimed to provide several strategic advantages. In particular, it sought to mitigate risks from fluctuating coal prices, relieve Guodian’s debt burden, and integrate Shenhua’s coal supply chain with Guodian’s renewable energy assets, thereby enhancing its competitive advantage.
This move aligned with broader state policies to create globally competitive, state-backed enterprises while potentially delaying domestic competition reforms. Additionally, the merger supported China’s efforts to reduce coal consumption and emissions.
3. ChemChina and Sinochem
Year: 2019
Deal value: $245 billion
Sinochem operates in oil, chemicals, and agricultural sectors, with notable assets like 32 oil and gas upstream projects in nine countries, a 15 million metric ton per year refinery in Quanzhou, and over 1,300 branded gas stations. ChemChina has significant operations in new chemical materials, agrochemicals, and oil processing, with four refineries totaling a capacity of 22.2 million metric tons per year.
The merger of these two state-owned Chinese companies aimed to consolidate their agricultural assets and enhance their capabilities in chemicals, biosciences, materials science, environmental science, and industrial finance.
The merger is now one of the biggest deals in history and the company is the world’s largest chemical conglomerate, with operations in over 150 countries and a workforce of more than 220,000 employees.
You can also find more merger and acquisition examples in our dedicated article.
4. United Technologies and Raytheon
Year: 2020
Deal value: $121 billion
In 2019, Raytheon Company and United Technologies Corporation announced their merger in an all-stock transaction, creating Raytheon Technologies. The deal, one of the biggest M&A deals of all time, closed in the first half of 2020, with United Technologies shareholders owning 57% of the new company and Raytheon shareholders owning 43%.
This merger combined United Technologies’ aerospace business, which included jet engines, cockpit controls, and airplane seats, with Raytheon’s expertise in missile systems, notably the Tomahawk missile.
The deal enabled the merging companies to gain access to each other’s customer bases and enhance cash flows, capitalizing on the booming aerospace industry. It resulted in annual sales of approximately $74 billion, making the combined company the second-largest aerospace and defense company in the U.S. by revenue, trailing only Boeing.
5. Dow Chemical and DuPont
Year: 2017
Deal value: $130 billion
On August 31, 2017, Dow Chemical and DuPont successfully completed their merger, forming DowDuPont. This new entity was structured into three separate companies: Agriculture, Materials Science, and Specialty Products. The merger aimed to create synergies and unlock value, with plans to separate into three independent, publicly traded companies within 18 months.
The Agriculture division combined the strengths of DuPont Pioneer, DuPont Crop Protection, and Dow AgroSciences. The Materials Science division incorporated Dow’s Performance Plastics, Performance Materials & Chemicals, and other segments along with DuPont’s Performance Materials. The Specialty Products division integrated DuPont Protection Solutions, Industrial Biosciences, and other technology-driven businesses.
This strategic move was expected to generate cost synergies of approximately $3 billion and growth synergies of about $1 billion. The separation into three focused companies aimed to provide higher value and greater opportunities for shareholders, customers, and employees.
6. Pfizer and Warner-Lambert
Year: 2000
Deal value: $90 billion
One of the biggest mergers of all time occurred in 2000, when Pfizer acquired Warner-Lambert in a deal valued at $90 billion, making the new entity the second-largest drug company globally. The acquisition was driven by Pfizer’s strategy to dominate the pharmaceutical industry and secure its profitable agreement on Lipitor, a cholesterol-lowering drug that was a major revenue source.
Despite Warner-Lambert’s initial resistance to Pfizer’s hostile takeover bid, the merger was finalized after three months of negotiations. The deal resulted in a substantial expansion of Pfizer’s sales force, adding 2,500 representatives to its existing 5,000. This increase, combined with a research team of 12,000, positioned Pfizer as a leader in the quickly evolving pharmaceutical industry.
The merger also aimed at cost-saving measures, with Pfizer planning to cut $1.6 billion in expenses by 2001. Although Warner-Lambert’s consumer products division, including brands like Listerine, was not a primary interest for Pfizer, it decided to retain this segment, managing it from Warner-Lambert’s headquarters in New Jersey.
7. Microsoft and Activision Blizzard
Year: 2022
Deal value: $75 billion
On January 18, 2022, Microsoft announced its intent to acquire Activision Blizzard for $68.7 billion. The acquisition, completed on October 13, 2023, ultimately amounted to $75.4 billion, making it the largest video game acquisition by transaction value in M&A history.
Microsoft integrated Activision Blizzard into its Microsoft Gaming division, alongside Xbox Game Studios and ZeniMax Media, gaining franchises like Call of Duty, Warcraft, Diablo, and Candy Crush.
The acquisition included a significant workforce restructuring, with Microsoft cutting 1,900 jobs from its gaming division and making leadership changes at Blizzard.
There also were several regulatory challenges that were overcome by transferring cloud gaming rights to Ubisoft for ten years to appease the UK’s CMA, while the US FTC withdrew its challenge after courts did not find their arguments compelling.
8. Walt Disney Company and 21st Century Fox
Year: 2019
Deal value: $71.3 billion
In March 2019, The Walt Disney Company completed one of the largest mergers in history, purchasing 21st Century Fox’s key assets. The deal included significant assets such as the 20th Century Fox film and television studios, FX Networks, a 73% stake in National Geographic Partners, Star India, and a 30% stake in Hulu. This acquisition allowed the acquiring company to significantly expand its content portfolio, customer base, and market share.
Fox Corporation retained assets such as the Fox Broadcasting Company, Fox News Media, and Fox Sports. Disney’s acquisition aimed to integrate these assets into its existing business operations, including the transformation of 20th Century Fox into 20th Century Studios. The merger also led to a restructuring of Disney’s television operations and a reorganization of its international business.
The strategic acquisitions were pivotal for Disney, aligning with its broader goal of enhancing its content library and expanding its streaming capabilities. Disney’s plan to phase out the Fox brand by 2024 was a deliberate move to prevent market confusion.
9. ExxonMobil and Pioneer Natural Resources
Year: 2024
Deal value: $60 billion
In 2024, ExxonMobil completed its acquisition of Pioneer Natural Resources in a transaction valued at $59.5 billion. This successful merger significantly expanded ExxonMobil’s presence in the Permian Basin, doubling its footprint and increasing its production capacity.
The combined entity now holds over 1.4 million net acres in the Delaware and Midland basins, with an estimated 16 billion barrels of oil equivalent in resources. ExxonMobil’s Permian production is projected to rise from 1.3 million to around 2 million barrels of oil equivalent per day by 2027. The merger integrates Pioneer’s extensive Permian acreage and expertise with ExxonMobil’s advanced technologies and financial strength, aiming to enhance resource recovery and operational efficiency.
Notably, the deal advances ExxonMobil’s environmental goals by accelerating Pioneer’s net-zero emissions target from 2050 to 2035. This strategic move is expected to improve shareholder value and support broader energy security and environmental objectives.
10. H.J. Heinz Co. and Kraft Foods Group
Year: 2015
Deal value: $45 billion
A merger between H.J. Heinz Co. and Kraft Foods Group created the Kraft Heinz Company. This deal positioned the new entity as the fifth-largest food company globally and the third-largest in the U.S. Under the terms, Heinz shareholders, including 3G Capital and Berkshire Hathaway, received a 51% stake in the new company, while Kraft shareholders got the remaining 49% and a one-time cash dividend of $16.50 per share, costing around $10 billion.
The merger aimed to leverage Heinz’s global presence and Kraft’s strong North American market, expecting to drive international sales growth and achieve $1.5 billion in annual cost savings by 2017. This synergy realization was anticipated from enhanced economies of scale, improved bargaining power with retailers, and refinancing high-yielding debt with lower-cost options.
The merger also promised the two firms operational efficiencies through zero-based budgeting and strategic cost controls, influenced by 3G Capital’s history of aggressive cost-cutting measures.
11. Liberty Global and Telefónica
Year: 2021
Deal value: $38.9 billion
In May 2020, Liberty Global and Telefónica announced a merger of their UK operations, creating a 50-50 joint venture between Virgin Media and O2. This merger aimed to form the leading fixed-mobile provider in the UK, combining Virgin Media’s fast broadband network with O2’s extensive mobile platform.
The expected synergies were worth £6.2 billion on a net present value basis, with annual benefits of £540 million by the fifth year post-closing.
The deal also included an investment of £10 billion in the UK over five years, enhancing digital infrastructure and expanding O2’s 5G and Virgin Media’s giga-ready network. Telefónica received £5.7 billion, and Liberty Global received £1.4 billion in net cash proceeds after recapitalization and equalization payments.
12. Sprint and Nextel Communications
Year: 2005
Deal value: $35 billion
In 2005, Sprint secured a majority stake in Nextel Communications with a $35 billion stock acquisition. This made the company the third-largest telecommunications provider in the world. The proposed merger created Sprint Nextel, a wireless giant with 35 million customers and a combined annual revenue of about $40 billion.
Sprint gained access to Nextel’s 15.3 million subscribers, many of whom were business customers, and avoided the need for Nextel to upgrade its network independently. The companies estimated $12 billion in savings from operating costs and network upgrades.
However, integrating the two companies proved challenging due to their differing wireless networks and clashing marketing strategies. Nextel’s popular “push-to-talk” service was primarily targeted at business users, while Sprint focused more on retail customers and data services. These differences made it difficult to merge operations smoothly, allowing competitors to steal dissatisfied customers.
13. Energy Transfer Equity (ETE) and Energy Transfer Partners (ETP)
Year: 2018
Deal value: $27 billion
One of the biggest acquisitions in history involved ETP combining with a wholly-owned subsidiary of ETE through a unit-for-unit exchange. Target company’s shareholders received 1.28 common units of ETE for each ETP common unit they own.
The merger aimed to streamline the organizational structure, align economic interests within the Energy Transfer family, and reduce leverage. By eliminating ETE’s incentive distribution rights in ETP, the transaction lowered the cost of equity capital and provided more cash for funding organic growth and future acquisitions. The consolidation also intended to strengthen the combined entity’s balance sheet by using cash distribution savings to reduce debt and support ETP’s growth capital expenditures.
This merger aligned with a broader trend among midstream operators adjusting their corporate structures due to changes in Federal Energy Regulatory Commission (FERC) policy affecting MLP tax benefits.
14. London Stock Exchange and Refinitiv
Year: 2021
Deal value: $27 billion
In January 2021, the London Stock Exchange Group (LSEG) finalized one of the biggest M&A deals in history — its $27 billion acquisition of Refinitiv, a leading data and trading company. This deal was a significant milestone for LSEG, as it merged two market leaders and highly complementary global businesses.
The acquisition received all necessary regulatory approvals after LSEG agreed to several concessions, including the divestment of its stake in the Borsa Italiana group, to address regulatory concerns.
The merger positioned LSEG as a global leader in financial data and infrastructure, enhancing its ability to offer comprehensive data, trading tools, analytics, and risk management services across international financial markets.
15. HP and Autonomy
Year: 2011
Deal value: $11.7 billion
In 2011, Hewlett-Packard (HP) announced its acquisition of Autonomy for $11.7 billion, paying a premium of around 79% over the market price, making it one of the largest acquisitions of all time This move was intended to shift HP’s focus from being primarily a computer and printer maker to a software-focused enterprise services firm.
Despite unanimous approval from the boards of the two companies, the deal quickly turned problematic. HP soon uncovered that Autonomy had manipulated its financials by selling hardware as software licensing revenue. By November 2012, HP announced an $8.8 billion write-down, citing serious accounting improprieties and misrepresentations at Autonomy. This announcement led to a significant drop in HP’s share price and raised concerns about fraudulent accounting practices.
HP faced massive lawsuits from shareholders due to the fall in stock value and accusations of mismanagement. External investigations by the Serious Fraud Office, U.S. Securities and Exchange Commission, and FBI were initiated, though the SFO eventually dropped its investigation. Cultural clashes and management conflicts between HP and Autonomy exacerbated the situation, leading to further scrutiny and controversy.
Explore our article on recent M&A deals to understand how these transactions impact market dynamics and company performance.
Lessons learned from historic M&A deals
Now let’s see what deal makers can learn from the described corporate acquisitions:
| M&A deals | Key lessons |
|---|---|
| America Online (AOL) and Time Warner |
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| China Shenhua Group and China Guodian Corporation |
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| ChemChina and Sinochem |
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| United Technologies and Raytheon |
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| Dow Chemical and DuPont |
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| Pfizer and Warner-Lambert |
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| Microsoft and Activision Blizzard |
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| Walt Disney Company and 21st Century Fox |
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| ExxonMobil and Pioneer Natural Resources |
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| H.J. Heinz Co. and Kraft Foods Group |
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| Liberty Global and Telefónica |
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| Sprint and Nextel Communications |
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| Energy Transfer Equity (ETE) and Energy Transfer Partners (ETP) |
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| London Stock Exchange and Refinitiv |
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| HP and Autonomy |
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Read our article on cybersecurity company acquisitions to learn about the latest trends and challenges in the cybersecurity sector.
Key takeaways
- Many high-value mergers face significant integration issues, such as cultural clashes and operational difficulties. Companies must anticipate and plan for these challenges to maximize the value of the deal.
- Mergers and acquisitions should align with strategic goals and create synergies. Whether it’s enhancing R&D capabilities, expanding geographic reach, or optimizing resources, a strong strategic fit can drive long-term success.
- Large mergers often face regulatory scrutiny and are influenced by market conditions. Understanding these factors is essential for navigating approvals and managing the timing and structure of the deal.
Studying past M&A transactions provides valuable insights into the complexities and challenges of high-value business deals. By analyzing these historic transactions, companies can better understand the importance of thorough due diligence, strategic alignment, and effective integration planning.
