A LinkedIn spokesman said, "The valuation marks the first time an internet company has reached the £500m mark since 2000, and surpasses recent valuations for other social media networks. This is an indication of the strength of the company's established business model and future opportunity."
The driver for LinkedIn's £500m claim is an injection of £26m from a number of venture capitalists led by new investor Bain Capital Ventures. Other firms to chip into this pot are existing investors Sequoia Capital, Greylock Partners, and Bessemer Venture Partners.
This fourth and largest round of funding "is based on the company's rapid member growth, multiple business models and future opportunity", said LinkedIn.
"LinkedIn's business model is a proven mix of revenues evolving beyond advertising, to include job search, subscriptions and corporate recruitment," it said.
The company has 23 million users worldwide and is growing rapidly.
Kevin Eyres, European managing director at LinkedIn, said,"Europe is an integral part of LinkedIn's growth strategy. The new funds will enable us to invest more heavily in the European market, a geography for whom networking and business knowledge-sharing continues to accelerate.
"The investment will help our members derive more value from their network so that each individual and business can more effectively compete on the global market,"