Priceline.com Inc., which is the biggest U.S. online travel agency by market value, reported a fourth quarter profit $226 million as total bookings rose more than 50 percent from a year ago to $4.96 billion.

Priceline reported a profit of $4.41 a share, up from $2.66 a share, a year earlier. The company also stated that sales increased 35 percent to $990.8 million from $731.3 million a year earlier.

Booking.com, the Amsterdam-based European unit that Priceline acquired in 2005, is the biggest source of its growth. More than 60 percent of the revenue of Priceline is coming from overseas, of which Europe has the maximum share.

Though the U.S. market was sluggish hotel bookings in Asia and Europe were strong. We believe that each of our brands, Booking.com, Agoda and priceline.com, gained share in the retail hotel room reservations market, while our Name Your Own Price hotel business in the United States continued to be impacted by increased competition in the discount market, Priceline CEO Jeffrey Boyd said in the press release.

The strong performance of the TravelJigsaw business, which was rebranded as rentalcars.com, received special mention. Our worldwide rental car reservation service delivered 34% growth in rental car days in the fourth quarter compared to the prior year, with rentalcars.com growing well in excess of that rate, Boyd said.

First-quarter profit will be $3.80 to $3.90 a share, excluding some items, Priceline said. Sales would rise 22 percent to 27 percent, Priceline added.