Facebook Inc.

Matt Cohler, a pivotal player in Facebook Inc.'s rapid growth, is departing the popular online hangout to find other promising Internet startups for a prominent venture capital firm.

Cohler will remain Facebook's vice president of product management through the summer and then become a general partner at Benchmark Capital, according to a Thursday announcement.

Even after joining Benchmark, Cohler will remain a "special adviser" to Facebook's 24-year-old founder and chief executive, Mark Zuckerberg.

Four venture capital firms are betting Internet startup LinkedIn Corp. is worth $1 billion, highlighting the lofty hopes riding on online services that connect people with their friends, family and business associates.

The 10-figure valuation is implied by a $53 million investment being announced Wednesday from Bain Capital Ventures, Sequoia Capital, Greylock Partners and Bessemer Venture Partners.

The investors received a combined 5 percent stake in Mountain View-based LinkedIn, whose 5-year-old Web site helps people use the Web to advance their professional careers.