Pret A Manger has been selling sandwiches since 1986

Pret's founders, thought to have made millions in the deal, are to reinvest a "significant" amount into the firm.

Pret had planned to auction the McDonald's-owned stake last year, but the deal collapsed over uncertainty in global financial markets.

Bridgepoint is interested in further expansion of the sandwich chain.

Pret a Manger currently has 200 shops, the majority in the UK. In 2008, the firm plans to open at least 30 new shops, including seven in New York. .

Founder Julian Metcalfe said: "Bridgepoint shares our vision, understands our culture and will support our roll-out plan globally."

Pret markets itself as an healthier, more ethically-sourced alternative to other fast-food outlets.

Bridgepoint recently bought clothing retailer Fat Face for £400m.