Shares of LinkedIn are rising in after-hours after better-than-expected first-quarter earnings.

NEW YORK (TheStreet) -- LinkedIn(:LNKD) shares jumped after the company posted better-than-expected first-quarter results, as revenue at its biggest unit more than doubled.

Mountain View, Calif.-based LinkedIn reported earnings of 15 cents per share on $188.50 million in revenue. Analysts polled by Thomson Reuters were expecting earnings of 9 cents per share on $178.58 million in revenue. Sales at Hiring Solutions soared 121% to $102.6 million. It accounted for 54% of revenue, up from 49% a year earlier.

"LinkedIn's solid performance in the first quarter built on the company's momentum in 2011," said CEO Jeff Weiner in the company press release. "We saw strength across all key metrics from member signups and engagement to significant revenue growth across our three product lines."

LinkedIn also gave greater-than-expected second-quarter revenue guidance, and raised its full-year outlook. The social-networking company expects second-quarter revenue to be between $210 million and $215 million.

Analysts polled by Thomson Reuters were looking for second-quarter guidance of 15 cents per share on $207.93 million in revenue.

Full-year revenue guidance was raised from a previous range of $840 million to $860 million to $880 million to $900 million.

The professional social network also announced it is acquiring SlideShare for $118.75 million in cash and stock. The acquisition is expected to close during the second quarter of 2012.

LinkedIn will hold a conference call at 5 p.m. EST to discuss the results.

Shares of LinkedIn finished the session higher, up 2.8% to close at $109.41. The shares extended that gain in after-hours trading, rising 10% to $120.65, according to Nasdaq.com.

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--Written by Chris Ciaccia in New York

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