Priceline.com Inc., the world’s largest online travel agency by market value, forecast first- quarter earnings that topped analysts’ estimates on projections that travel bookings will increase as much as 50 percent.

Profit this quarter, excluding some items, will be $2.34 to $2.44 a share, the company said today in a statement. Analysts on average predicted $2.30, according to a Bloomberg survey. Sales will grow at least 29 percent from a year earlier, to $753.9 million, compared with estimates of $731.9 million.

The e-commerce company, which offers airfare, hotel bookings, vacations and car rentals, said total travel bookings will increase 45 to 50 percent this quarter from a year earlier. International bookings will rise as much as 69 percent, the company said.

Priceline, based in Norwalk, Connecticut, rose as much as 7 percent to $456 in extended trading. The shares dropped $7.79 to $425.99 at 4 p.m. New York time on the Nasdaq Stock Market. The shares have climbed 6.6 percent this year.

Fourth-quarter net income rose 73 percent to $135.7 million, or $2.66 a share, from $78.5 million, or $1.55, a year earlier. Excluding one-time items, profit was $3.40 a share, exceeding the $3.10 average of estimates compiled by Bloomberg. Sales rose 35 percent to $731.3 million.