Wal-Mart, the world's largest retailer, has reclaimed its position as the largest corporation in the U.S. among the Fortune 500, pushing Exxon Mobil down to number two.
With more than $351 billion dollars in revenue, the magazine ranks Wal-Mart slightly ahead of the energy giant. Wal-Mart is on top for the fifth time in six years.
Oil companies have three of the top five spots, with Chevron at No. 4 and ConocoPhillips at No. 5, bumping Ford Motors to No. 7. Fellow auto giant General Motors came in at No. 3.
CNBC's parent General Electric took the sixth spot and was one of the most profitable companies in 2006. The others were Exxon Mobil, UAL , Citigroup and Bank of America.