Shares of LinkedIn Corp. are diving Thursday after the professional networking service gave a disappointing second-quarter outlook.

LinkedIn said the weak view was due to changes in currency exchange rates, costs of its pending acquisition of online learning company Lynda.com and other items.

The $1.5 billion deal announced earlier this month is by far the largest in LinkedIn's history.

For this quarter, Mountain View, California-based LinkedIn expects adjusted earnings of 28 cents per share on revenue of $670 million to $675 million.

Analysts are forecasting much higher adjusted earnings of 74 cents per share on revenue of $719.3 million, according to a poll by FactSet.

The Lynda acquisition is expensive, but LinkedIn is "building a great long-term business," said BGC Partners analyst Colin Gillis.

He also said there's often a sharp market reaction to LinkedIn's earnings, with the stock moving at least 6 percent in the last eight quarters and 10 percent or more in half of them.

LinkedIn's stock tumbled $63.93, or 25 percent, to $188.20 in extended trading. The stock had closed down 2 percent.

LinkedIn's stock plunge follows a disappointing report from Twitter Inc. earlier this week which sent that company's stock down sharply as well.