Private equity firm Cinven is reported to be advanced talks to buy travel company Tui AG's online booking business Hotelbeds, in a deal that could fetch up to €1bn (£780m).
Hotelbeds provides rooms to travel agencies, tour operators and airlines through a database of more than 75,000 hotels worldwide.
It was put up for sale last year after Tui hired Deutsche Bank and Bank of America to advise on the process. The deal is expected to be valued at around €1bn.
Cinven is understood to be the frontrunner to buy the business after outbidding other rival buyout firms, according to Bloomberg.
In 2014, the German company merged with London-listed Tui Travel, which it already controlled, to create the world's largest leisure tourism group.
Tui's chief executive Friedrich Joussen has since been focussing on expanding the merged group's hotels and cruise business, while scaling back its online activities. It sold LateRooms in October to travel firm Cox & King.
Cinven and Tui declined to comment.