Oil giant Exxon Mobil takes pole position
Global retail giant Wal-Mart has been knocked off the top spot of the Fortune 500 by oil company Exxon Mobil. The US-based owner of Asda held the top spot for four years.

The list, compiled by US magazine Fortune, ranks the top 500 US companies by revenue. Soaring energy prices are thought to be responsible for Exxon's rise.

Exxon's revenue was US$339.94 billion compared with Wal-Mart's US$315.65 billion. Profits were US$36.13 billion and US$11.23 billion respectively.

General Motors takes third place in 2006's list.