Getty Images has attracted bids of around $4 billion from private-equity firms interested in acquiring the Seattle-based photo agency, The Wall Street Journal reported on its website Tuesday.

Getty, which was publicly traded before a 2008 leveraged buyout valued at $2.4 billion, reportedly is considering a new initial public offering to provide an exit for its main owner, San Francisco investment firm Hellman & Friedman. But the strong interest reported among private investors, and an uncertain IPO market, could make reselling Getty to another private equity firm more appealing.

The Journal said Getty co-founder and chairman Mark Getty is expected to keep his minority stake in any deal with a new private-equity buyer.

A deadline for the second round of bidding hasn't been set, it said.

A Getty spokeswoman could not be reached for comment.