Oil giant Exxon Mobil Corp. surpassed automaker General Motors Corp., rising to No. 1 from No. 3 with the company's highest-ever $210 billion in revenue for 2000. GM, which had revenue of $184.6 billion, fell to No. 3. 

Other energy companies fared well in 2000, with Enron Corp., at No. 7, rising from No. 18. Duke Energy Corp. shot up to No. 17 from 69 and Reliant Energy Inc. made it up to No. 55 from 114. 

The list of the largest publicly held companies, ranked by fiscal year 2000 revenues, has been compiled annually since 1955 by the editors of Fortune. GM, which had held the top spot on the list for 15 years, now trails No. 2 Wal-Mart Stores Inc. in addition to Exxon Mobil. 

Energy companies benefited from a surge in revenue brought about by falling supplies, utility deregulation, soaring natural gas prices and OPEC's maneuvering to keep oil prices high. In the past year, crude oil has sold for as much as $30 a barrel, while in some parts of the United States last summer, gasoline cost more than $2 a gallon. 

Other energy firms advancing included Texaco Inc., which went from No. 28 to No. 16; Chevron Corp., which was ranked No. 20, up from No. 35; and Dynegy Inc., which rose to No. 54 from No. 112. 

San Francisco-based Chevron agreed to buy Texaco last October for $35.1 billion in stock, plus assumed debt of $7.5 billion. The deal is expected to close this summer pending review by the U.S. Federal Trade Commission. 

The Internet slowdown and uncertainty about the economy hurt a number of companies, particularly telecom firms that slid in the rankings. AT&T Corp. fell from No. 8 to No. 9. 

But a merger helped Verizon Communications Inc., formed when Bell Atlantic and GTE combined in May, leapfrog from No. 33 past rivals WorldCom Inc., No. 32, and SBC Communications, No. 14, to the No. 10 spot. 

America Online Inc., which became the first purely Internet company to break into the list last year at No. 337, rose to No. 271. Since then, it has become AOL Time Warner Inc. by dint of its acquisition of Time Warner. The combined company's revenue of $36.2 billion would have made it No. 39 on the new list, though was not counted there because the deal didn't close until early this year. 

Computer companies were led by International Business Machines Corp., which stayed in the top 10, but fell from sixth last year to No. 8. 

Microsoft Corp. rose to 79 from 84, and Cisco Systems Inc., which makes equipment for the Internet, advanced to 107 from 146, despite the dot-com crash. 

PC maker Dell Computer Corp. rose to 48 from 56 and Apple Computer Inc. rose from 285 to 236. Compaq Computer Corp., meanwhile fell from 20 to 27. 

Wal-Mart, which remained in the No. 2 spot, had revenues of more than $193.2 billion. It draws the distinction as being the company with the most employees on the list, more than 1.2 million worldwide. 

The top 10 also included Ford Motor Co. at No. 4, a position it held last year. General Electric stayed at the No. 5 position while Citigroup Inc., the largest financial services company in the nation, rose from seventh place to No. 6. 

The highest ranked new company on the list is No. 57 Delphi Automotive Systems Corp., which was spun off by GM in May 1999. 

Total profits for the 500 corporations grew 8.4 percent for the year, down from 1999's level of 28.7 percent, to $444 billion. Revenue grew by more than 13 percent to a combined $7.2 trillion for 2000. The 500 companies employed more than 24 million workers.