Bessemer Venture Partners

LinkedIn Corp. has raised an additional $22.7 million to help insulate the steadily growing online business network from the economic storm and provide more financial flexibility.

The investment announced Thursday was made by one of LinkedIn's long-time backers, Bessemer Venture Partners, and three newcomers -- business software maker SAP Ventures, banker Goldman Sachs Group Inc. and The McGraw-Hill Companies Inc., which publishes Business Week.

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.