Discount travel website Priceline.com (PCLN) decided long ago to carve out a niche in European travel. That strategy worked well for years, but is now hurting the company as Europe's economy flags.

Priceline shares were tanking Wednesday, falling more than 16% to $569.09 from Tuesday's closing price of $679.80. The company posted a decent quarter Tuesday, but gave a disappointing outlook for the current quarter based largely on continued European weakness.

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Another online travel company, Orbitz (OWW), saw shares drop 24% to $3.54 after reporting disappointing earnings. Even Expedia (EXPE) dropped in sympathy Wednesday, falling more than 5% to $55.57.

Here's what's bringing down each company:

Priceline.com
The company blew away analyst expectations on profit, reporting net income of $352.3 million, or $6.88 a share, which was up from $256.4 million, or $5.02 a share, a year earlier. When you take out compensation costs and other one-time items, net income rose to $7.85 a share, far higher than the $7.36 a share analysts expected.

Revenue was a slight disappointment at $1.33 billion, which was a 20% spike from a year earlier. Analysts wanted to see $1.35 billion.

Those numbers alone would have been OK for the stock. But Priceline investors fled after the company's third-quarter forecast, in which it estimated earnings at between $11.10 and $12.10 a share -- far below the $12.82 a share analysts were expecting. The company also pegged revenue at 9% to 15% higher than a year earlier, or about $1.58 billion to $1.67 billion. Analysts were looking for $1.8 billion.

"Guidance was a lot worse even off of lowered expectations," wrote Susquehanna analyst Herman Leung in a note to clients.

Orbitz
Earnngs and revenue fell for the company in the quarter. Profit was $4.6 million, or 4 cents a share, from $8.9 million, or 8 cents a share, a year earlier. Revenue fell to $200.9 million from $201.8 million. Analysts expected 6 cents per share in profit on revenue of $208.2 million.

The company's third-quarter guidance also disappointed analysts on both earnings and revenue. Orbitz said it expected between $32 million and $38 million before interest, taxes, depreciation and amortization. It also estimated revenue at $197 million to $203 million.

Expedia
The company reported a strong quarter last month, handily beating expectations with a profit of $105.2 million, or 76 cents a share, on revenue of $1.04 billion. The company didn't necessarily deserve the drop its shares saw Wednesday, since its strength is in corporate travel bookings and online advertising revenue.

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