Kayak is being bought by rival Priceline just months after going public.
Priceline has agreed to pay $1.8 billion in cash and stock for the company, making this the largest acquisition in Priceline’s history.
The deal is expected to be completed at the end of the first quarter of 2013.
In a statement, Priceline said Kayak’s management team will continue to manage the operations independently.
"Kayak has built a strong brand in online travel research and their track record of profitable growth is demonstrative of their popularity with consumers and value to advertisers," said Priceline Group president and CEO Jeffery H. Boyd.
"Kayak also has world class technology and a tradition of innovation in building great user interfaces across multiple platforms and devices. We believe we can be helpful with KAYAK’s plans to build a global online travel brand."
Kayak was started by Paul English and Steve Hafner eight years ago.
"The Priceline Group’s global reach and expertise will accelerate our growth and help us further develop as a company," said Hafner.
