Exosphere was founded in 2006 by John Saunders and offers tailormade holidays to wealthy clients.
Luxury agency and operator Oxford Private Travel is a sister company to The Oxford Ski Company, which was founded by Rupert Longsdon in 1998.
The acquisition will see Exosphere “folded into” the Oxford Private Travel brand, which will open a new London office.
Longsdon said: “I am delighted about this acquisition. I have known John and Exosphere for many years and Exosphere will naturally complement our business having similar values, an engaging and warm culture and extensive skill set.
“It also highlights our desire to grow our Oxford Private Travel brand.”
The deal does not include buying Exosphere Events, which be rebranded as Origination and will continue to be run by Saunders and current events director Sophie Edwards.