LinkedIn, the biggest professional-networking website, reported first-quarter sales and profit that topped estimates.

The company also agreed to buy SlideShare, a professional content-sharing site, for about $118.8 million in cash and stock.

Sales for the quarter more than doubled to $188.5 million. Net income increased to $5 million, or 4 cents a share, from $2.08 million, a year earlier.

LinkedIn shares gained 2.8 percent to $109.41.