Mergers may be effected to increase profits and reduce losses through the reduction of competition, to diversify production, to protect against the liabilities of concentration in a single area, or to revive or rejuvenate failing businesses by the infusion of new management and personnel. Mergers for monopolistic purposes were among the unfair practices that the Sherman Antitrust Act (1890) and, more especially, the Clayton Antitrust Act (1914) attempted to correct. The international nature of many modern corporations now also subjects mergers to antitrust scrutiny overseas, particularly in the European Union.
The end of the 20th cent. witnessed a great increase in mergers; in the United States alone, 60,375 mergers involving a total of over $4.5 trillion occurred between 1980 and 1996. Among the largest recent U.S. mergers are those between America Online and Time Warner (2000; $165 billion, but worth significantly less after the bubble in Internet-related stocks collapsed), Exxon and Mobil (1999; $81 billion); Citicorp and Travelers Corp. (1998; $72.6 billion), AT&T and Bell South (2006; $67 billion), SBC Communications and Ameritech (1998; $60.1 billion), and AT&T and TCI (1999; $48 billion).
See also conglomerate.
A de facto non-merger is when the merger takes the form of a merger but in substance it is a non-merger. It is done to avoid some of the liabilities and responsibilities that go along with an asset sale or other non merger transactions. A shareholder will argue de facto non merger and claim that although the transaction took the form of a merger in actually the corporation wished to effectuate a transaction other than a merger and therefore the corporations owes the shareholders the rights they hold under those non merger requirements