The growth capital fund of Google Inc. (Nasdaq: GOOG), Google Capital, has made a $50 million investment in Auction.com LLC.

Auction.com allows users to buy and sell real estate, including bank-owned homes, foreclosures, other residential properties, commercial properties and land, online. The Irvine, Calif.-based company hosts online auctions for the properties.

"We can deploy some of this capital to build out our product suite for both online and mobile products, and it will facilitate hiring some of the talent we need in order to do that," says Auction.com executive vice president Rick Sharga.

The site is backed by Greenwich, Conn.-based private equity firm Stone Point Capital, which picked up a stake in the company in November 2008. Other shareholders include Starwood Capital Group, Starwood Property Trust and funds managed by affiliates of Fortress Investment Group.

Google Capital will own a minority stake in the business. As part of the deal, one representative from Google Capital will join Auction.com's board of directors and another will take a board observer position.

"Considering that we're an online marketplace, to find a partner that probably is the best company in the world at digital marketing, and has expertise they can share with us in terms of online and mobile development just made this a perfect fit," Sharga says.

Before Auction.com, Google Capital invested in Renaissance Learning, a learning analytics group, Lending Club, an online credit marketplace for loans, and survey company SurveyMonkey.

JPMorgan Securities LLC served as sole private placement agent for Auction.com.