3i Group is to invest £159 million in specialist operator Audley Travel.
The deal will see Equistone Partners Europe exiting its investment, and the existing management team including chief executive Ian Simkins and chairman Richard Prosser will remain in place.
Audley Travel specialises in tailor-made itineraries and is forecast to deliver revenues of about £165 million in 2015, a 20% increase on 2014.
Tom Salmon, director of 3i, said: “Audley is an excellent fit for our investment strategy of backing mid-market businesses to grow internationally.
“It is a market leading business which delivers outstanding service to its clients and which is capitalising on the growing demand in both the UK and the US for high quality, genuinely tailored experiential travel.
“We look forward to working with Ian, Richard and the rest of the team to continue grow the business in both its existing and new markets.”
Simkins said: “We are delighted to be partnering with 3i which has enabled our management team to invest further into the business.
“3i has a longstanding track record of supporting people based businesses and their international mindset and footprint is highly attractive to us as a management team.
“We look forward to working with the 3i team as we pursue our growth ambitions by building upon the success we’ve achieved over the last three years with the support and backing of Equistone.”
Founders Craig Burkinshaw and John Brewer have held talks with a number of private equity firms since signalling the luxury tour operator was for sale earlier this year.
Head of mergers and acquisitions at accountancy and business advisory firm BDO, Peter Hemington, told ITT overseas conference delegates in June that Audley Travel would be sold for £200 million and in November 3i rival KKR was believed to be close to sealing a deal.
Burkinshaw and Berger founded Audley 20 years go and private equity investors Equistone Partners Europe took a stake in the business for around £90 million in 2012.
The operator employs around 250 people in Oxfordshire and close to 350 in total. It opened its first US office in Boston and a London base last year.