Revenue in the U.S. has dropped for seven straight quarters.
Fortune Magazine's annual ranking, released Thursday, was filled with examples of how rising fuel prices are affecting the economy. Wal-Mart was followed by three largest American oil companies: Exxon Mobil Corp., Chevron Corp. and ConocoPhillips.
Fortune, which compiled its closely watched list based on revenue for 2010, said that America's top companies profited by boosting productivity and cutting jobs. Like Wal-Mart, they also relied on growing operations overseas. The strategy helped them increase earnings 81 percent to $318 billion. That's the third-largest combined profit gain in the list's history.
"We've rarely seen such a stark gulf between the fortunes of the 500 and those of ordinary Americans," editors of the list wrote.
Fannie Mae jumped from 81st last year to round out the top 5, though the rise was mostly due to new accounting rules and continued support from the federal government. The company also faces an investigation by the Securities and Exchange Commission, which is looking into statements that former CEO Daniel Mudd made about the mortgage giant's exposure to risky loans.
General Electric Co., Berkshire Hathaway Inc., General Motors Co., Bank of America Corp. and Ford Motor Corp. rounded out the top 10.
Ten companies cracked the list for the first time this year.
Nineteen others, including Chrysler and Fidelity National Information Services, returned to the Fortune 500 this year.
The list now includes just one newspaper company, Gannett Co. Inc., at No. 415. A decade ago, five newspaper companies were among the top 500.