New York  - The global economic crisis has scrambled the pecking order among US firms, with Exxon Mobil ousting Wal-Mart as the top revenue-earning company.

The energy company vaulted to the top of the business magazine Fortune 500 list, pushing the world's largest retailer to second place.

Profits among Fortune 500 companies saw the worst declines in the list's 55-year history, falling 85 per cent in 2008 compared to 2007, for total losses of 99 billion dollars.

The rankings were published Sunday on the internet. Following on the top ten list were Chevron, General Motors, ConocoPhillips, General Electric, Ford Motors, Citigroup, Bank of America and AT&T. (dpa)