Kayak shareholders yesterday voted overwhelmingly to approve a merger with Priceline.com.
Around 96% voted in favour of the deal which was announced in November, valuing online travel research site Kayak at $1.8 billion.
Priceline president and chief executive Jeffery Boyd said: "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.
"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 chief executive and co-founder Steve Hafner added: "The Priceline Group's global reach and expertise will accelerate our growth and help us further develop as a company."
There had been claims from shareholders that Priceline and Kayak had not succeeded in realising the true value of the price comparison site in negotiating the deal.
However, it was reported last month in the US that potential lawsuits that could have blocked the deal had been settled.