Outsourcing service oDesk, which brokers jobs between freelance workers and businesses looking to outsource, announced today it has raised $15 million in its fourth round of funding.

“oDesk helps find and match clients with contractors and helps them work together as if they are in the same office,” said Gary Swart, chief executive of oDesk in an interview with VentureBeat, “We can prove how much time is worked and guarantee the contractor gets paid, even if we don’t collect money from the client.”

Many startups and large companies are choosing to outsource work to contractors to cut costs and find better talent. As a result, services like oDesk have popped up and grown a large community of freelancers looking to find work. oDesk has found itself growing quickly and edging out its competition, which includes freelance contracting sites Elance and PeoplePerHour. Swart tells me that oDesk has doubled its business each year since 2007 and currently has a community of 1.6 million contractors. He also says its community of freelance workers earn $300 million each year.

While Swart tells me that oDesk is the largest company in the contract hiring space, it is not without competition. Elance is one of its biggest competitors with more than 120 percent growth from 2010 to 2011. Elance secured $15 million in funding in January 2012, proving that the online contracting industry is growing.

oDesk and Elance have different business models, but both compete for similar contractors and clients. oDesk focuses on longer projects and only offers hourly paid jobs, while Elance contractors must bid on either flat rate projects or hourly jobs, most of which provide short-term work.

The $15 million round oDesk received was led by Henry Ellenbogen of T. Rowe Price, Benchmark Capital, Globespan Venture Partners, and Sigma Partners.

“We’ll use the funding to continue to scale the business, developing new products our customers want, and hire more people,” said Swart.

oDesk has 75 full-time employees and 200 equivalent full-time contractors, and it manages and pays its staff using its own platform. To date, oDesk has received $44 million in funding from T. Rowe PriceBenchmark CapitalSigma PartnersGlobespan Capital Partners, and DAG Ventures. The company is based in Redwood City, Calif.

Outsourcing image via ShutterStock