the original company. Since the breakup of Standard Oil, several companies, such as General Motors and Microsoft, have come under antitrust investigation for being inherently too large for market competition; however, most of them remained together. The only company since the breakup of Standard Oil that was divided into parts like Standard Oil was AT&T, which after decades as a regulated natural monopoly, was forced to divest itself of the Bell System in 1984. Successor companies Standard Oil's breakup split the company into 43 separate companies. Several of these companies were considered among the Seven Sisters who dominated the industry worldwide for much of the 20th century, and both Standard Oil's direct and indirect descendants make up Big Oil. Today, Standard Oil's influence is primarily concentrated in a few companies: ExxonMobil, continuation of Standard Oil of New Jersey (later Exxon) which merged with Standard Oil of New York (later Mobil) Chevron, continuation of Standard Oil of California which acquired Kentucky Standard BP, continuation of the Anglo-Persian Oil Company which acquired Standard Oil of Ohio and Standard Oil of Indiana Marathon Oil and Marathon Petroleum, continuations of The Ohio Oil Company ConocoPhillips and Phillips 66, continuations of the Continental Oil Company Many of today's largest oil and gas companies are or have acquired a descendant of Standard Oil. Moreover, many other companies have acquired or been created from Standard Oil descendants over time, including Unilever (which acquired Standard descendant Vaseline in 1987), TransUnion (created originally as a holding company for Standard descendant Union Tank Car) and Berkshire Hathaway (which later acquired Union Tank Car). Rights to the name Of the 43 "Baby Standards", 11 were given rights to the Standard Oil name, based on the state they were in. Conoco and Atlantic elected to use their respective names instead of the Standard name, and their rights would be claimed by other companies. By the 1980s, most companies were using their brand names instead of the Standard name, with Amoco being the last one to have widespread use of the "Standard" name, as it gave Midwestern owners the option of using the Amoco name or Standard. Three supermajor companies now own the rights to the Standard name in the United States: ExxonMobil, Chevron Corp., and BP. BP acquired its rights through acquiring Standard Oil of Ohio and merging with Amoco and has a small handful of stations in the Midwestern United States