Priceline.com Inc. announced Nov. 8 that it has signed a definitive agreement for the Priceline Group to acquire KAYAK in a stock and cash transaction that is valued at $1.8 billion, or $40 per share of KAYAK.

The boards of directors of the Priceline Group and KAYAK have unanimously approved the transaction, which is subject to customary closing conditions, including a vote of KAYAK's shareholders and regulatory approvals, and is expected to close by late first quarter of 2013.

KAYAK's current management team will continue to manage KAYAK's operations independently as part of the Priceline Group of companies. Priceline said it expects the impact of the KAYAK acquisition on non-GAAP earnings per share to be minimal in 2013.

KAYAK is a leading travel research site that allows people to compare hundreds of travel sites when searching for flights, hotels and rental cars. The company processes more than 100 million user queries each month through its global websites and mobile applications.

"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 Chief Executive Officer 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."

The Priceline Group includes more than 270,000 participating hotels worldwide and is composed of four primary brands: Booking.com, Priceline.com, Agoda.com and Rentalcars.com, as well as several ancillary brands.