The Burger King fast food chain has been bought by Brazilian investment fund, 3G Capital, which is run by Jorge Paulo Lemann, who ranks 48 in Forbes list of billionaires.

The Brazilian investment fund announced on Monday that it had signed a deal valued at approximately US$4 billion.

Once the deal is through, it will become the largest leveraged acquisition of a fast-food chain ever.

Mr Lemann is backed by a number of wealthy Brazilians, who have said they wish to expand Burger King internationally, especially in Latin America and Asia.

The fast-food chain has recently struggled in North America, due to weak consumer demand and high prices for commodities such as wheat and beef.