Sandwich chain Pret a Manger is in talks with private equity firm Bridgepoint, to buy out McDonald's' 33% stake together, the BBC has learned.
Pret a Manger was founded in 1986
Pret's founders and majority owners, Julian Metcalfe and Sinclair Beecham, are "highly likely" to seal a deal, sources have revealed.
The transaction, set to be completed this month, is said to be worth £350m.
The founders, who launched the firm in 1986, are expected to maintain a significant investment in the firm.
McDonald's bought its share in the company in 2001.
In December 2007, it was reported that a planned auction of the firm collapsed, after Lion Capital, PPM Capital, FL Group, Morgan Stanley and Advent all withdrew from the process.
Pret a Manger has marketed itself as a healthy alternative to fast-food outlets.
Pret has about 150 outlets with the majority based in the UK. As well as selling through its stores, it also offers a delivery service.