The World’s biggest companies

Exxon MobilThe oil giant retook top spot yesterday, with a market cap of $385.65bn (£253.22bn).

AppleApple has seen a dramatic fall in its share price over the past six months. Its market cap has fallen from $656bn in September to $378.25 today.

GoogleThe search engine giant has a current market cap of $259.13bn.

Wal-MartThe supermarket giant and Asda owner is the world's third biggest company, with a market cap of $258.49bn. By comparison, Tesco in the UK has a market cap of $45.52bn.

MicrosoftThe company founded by Bill Gates has a market cap of $241.45bn,

General ElectricGE, which makes everything from medical products to aerospace equipment and credit cards, has a market cap of $236.04bn.

Johnson & JohnsonThe Listerine maker has a market cap of $234.67bn.

IBMThe American technology company has a market cap of $233.68bn.

ChevronEnergy company Chevron has a market cap of $223.04bn.

PfizerIn tenth place is drugs maker Pfizer, which has a market cap of $221.82bn.

All ten of the world's biggest companies are listed in America. Shell, Britain's biggest listed company by market cap, is valued at $205.8bn, while HSBC, also listed in London, has a market cap of $189.91bn.Samsung is the largest listed company in Asia. The electronics giant is valued at $199.18bn, while Toyota, listed in Japan, is valued at $196.45bn.