Priceline announced in November that it had signed an agreement to acquire Kayak in a deal valued at $1.8 billion ($40 per share of Kayak). Priceline would pay about $500 million in cash and $1.3 billion in equity and assumed stock options.

The Federal Trade Commission reportedly said that it has granted its approval of the deal. Reuters reports that the deal was one of several on a list of approved transactions that the FTC announced.

Priceline CEO said when the deal was announced, “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 CEO Steve Hafner added, “Paul English and I started Kayak eight years ago to create the best place to plan and book travel. We’re excited to join the world’s premier online travel company. The Priceline Group’s global reach and expertise will accelerate our growth and help us further develop as a company.”

Both boards approved the transaction. Priceline had indicated in November that it expected the deal to close by late first quarter 2013.

Kayak will remain a separate entity under Priceline, and will keep its current management staff. Kayak processes over 100 million user queries per month.

It remains to be see whether Kayak will remain part of the FairSearch coalition, as Priceline is not a member. When asked about this initially, FairSearch would not comment on the matter.