Expedia Inc., the online-travel booking service, will acquire Orbitz Worldwide Inc. for $12 a share in cash, adding brands such as CheapTickets, ebookers and HotelClub to take on industry leader Priceline Group Inc.

The deal price represents a premium of 25 percent to Orbitz’s closing price Wednesday. The transaction is valued at about $1.6 billion, including net debt, the companies said in a statement. Bellevue, Washington-based Expedia is adding consumer travel brands, including CheapTickets, as well as business-to- business sites such as Orbitz Partner Network.

The online-travel industry has seen a boom in mergers and acquisitions recently. Last month, Expedia also agreed to acquire Sabre Corp.’s Travelocity for $280 million in cash, as it tries to bulk up against competitors like Priceline. Last year, Priceline, the largest online-travel company, bought a minority stake in Ctrip.com International Ltd. and paid about $2.5 billion to purchase restaurant-reservations website company OpenTable Inc.

Orbitz had been exploring a sale and reaching out to potential buyers, Bloomberg News reported last month, citing people with knowledge of the matter. The company has long been the smallest player in online travel without the benefit of economies of scale, Daniel Kurnos, an analyst at Benchmark Co., said at the time.

Expedia rose 8 percent to $84.50 at 8:36 a.m. New York time. Orbitz soared 23 percent to $11.80. Through Wednesday, Expedia shares had fallen 8.4 percent this year.

Private equity firms have also displayed interest in acquiring travel companies. In January, TA Associates invested in RateGain, and before that, in May, Thoma Bravo paid $930 million for TravelClick. 

--Additional reporting by Allison Collins