SAN FRANCISCO -- LinkedIn finished last year with a solid financial performance, but the online professional networking service spooked investors with a forecast indicating that its growth is starting to slow down.

The projection released Thursday along with LinkedIn's fourth-quarter results triggered a 10 percent drop in the company's stock price in extended trading.

The sell-off came a day after Twitter Inc., another Internet service that connects people with common interests, let down Wall Street with a slowdown in its user growth.

LinkedIn's fourth-quarter earnings and revenue topped analyst estimates.

The Mountain View company earned $3.8 million, or 3 cents per share. That was down 67 percent from $11.5 million, or 10 cents per share, a year earlier.

Revenue climbed 47 percent from the previous year to $447 million.