Sabre Holdings, owner of website Lastminute.com and Travelocity, is to be bought for $4.5bn (£2.2bn) by US venture private equity companies Silver Lake Partners and Texas Pacific Group.
It is understood that the travel and leisure brands will be retained and that the two websites will continue to operate as usual.
Sabre Holdings bought Lastminute.com, launched in 1998 by Brent Hoberman and Martha Lane Fox, for just over $1bn (£573m) last year.
Hoberman stood down as chief executive earlier this year while Lane Fox left the business in 2003. Marketing director Mat Hart also left the company this year and is yet to be replaced.