NORWALK, Conn. (AP) — Discount travel website Inc. said Tuesday that profit and revenue rose in the second quarter on strong bookings for international travel, but it gave a disappointing forecast of third-quarter results, citing the weak economy in Europe.

Priceline shares tumbled more than 15 percent in extended trading.

Priceline said its third-quarter outlook assumed that Europe's economy will continue to weaken due the debt crisis and concern about the euro's future. Much of Priceline's business is based on European travel.

The company predicted that third-quarter earnings, excluding items, would be between $11.10 and $12.10 per share, below analysts' expectation of $12.82 per share.

Priceline said revenue will be 9 percent to 15 percent higher than last year's third quarter, which suggests a range of between $1.58 billion and $1.67 billion. That would be less than the $1.80 billion that analysts expect.

In the second quarter, the company rode a wave of strong bookings for international travel. Revenue from those rose 40 percent. Hotel bookings soared 39 percent and the car-rental business grew 29 percent over the same quarter last year.

Net income was $352.3 million, or $6.88 per share, compared with $256.4 million, or $5.02 per share, a year earlier. The company said that excluding stock-based compensation expenses and other items, it would have earned $7.85 per share.

Analysts, who usually exclude special items, expected $7.36 per share, according to FactSet.

Revenue rose 20 percent to $1.33 billion from $1.10 billion a year earlier. Analysts forecast $1.35 billion.

Customers used the site to make $7.3 billion in travel bookings, including taxes. That's up 27 percent from a year ago.

The company boosted online advertising spending by one-third, to $314.5 million. It spent just $9.9 million on other forms of advertising.

Before the results were released, Priceline shares rose $14.68, or 2.2 percent, to close at $679.80. In after-hours trading, they fell by $104.30, or 15.3 percent, to $575.50.