US banking giant Citigroup has been named the largest company in the world, by Forbes business magazine.

The New York-based firm topped Forbes' Global 2000 list, which is based on a composite of sales, market value, assets and profits.

Bank of America came second, with HSBC Holdings third, General Electric fourth and JPMorgan Chase fifth.

Citigroup, which also topped last year's list, made an annual net profit of $21.54bn on revenues of $146.56bn in fiscal 2007.

The company has assets totaling nearly $1.9 trillion and a market value of about $250bn.

Other companies that made the top 20 include British oil giant BP, Japanese car manufacturer Toyota and US insurance firm Berkshire Hathaway.

According to Forbes' list, retail chain Wal-Mart Stores is the world's richest company by revenue, while British bank Barclays is the biggest firm by assets.

US oil giant ExxonMobil is the most profitable firm on the planet as well as being the largest company by market value.

Citigroup, formed through a merger of Citicorp and Travelers Group in 1998, has just under 300,000 employees and over 200 million customer accounts in more than 100 countries.

The firm owns brands such as Citi Cards, CitiFinancial, CitiMortgage, CitiInsurance, Primerica, Diners Club, The Citigroup Private Bank and CitiCapital.

Earlier this year, Citigroup made an offer of $10.8bn for Japan's third-largest brokerage, Nikko Cordial.

If approved, the deal would be the largest takeover of a Japanese company by a non-Japanese firm.