Private equity firm Blackstone Group is deep into preparations for an initial public offering of the entire firm, according to a report Friday, a move that would be counter to the views of its CEO on the public markets.

Blackstone is working with investment bank Goldman Sachs Group Inc. (GS) on an IPO prospectus that could be filed in the next couple of weeks, business news channel CNBC said Friday. The report said that the ultimate decision on whether to go public has not yet been made.

Blackstone and Goldman Sachs declined to comment on the report.

Blackstone CEO Stephen Schwarzman has repeatedly said that he is not interested in an IPO of the firm or its various divisions.

"I think the public markets are overrated," Schwarzman said, speaking on a panel on Feb. 27 at the annual Super Return private equity conference. When referring to the efforts of a rival that pursued an offering a year earlier, Schwarzman said "To divert yourself like that and then take on that cost, is really not worth it."

The report on Blackstone's IPO plans come amid speculation that more private equity and hedge funds will seek public money after the IPO last month of Fortress Investment Group LLC, a private investment fund which raised more than $600 million.

Less than two years ago, Schwarzman told CNBC that Blackstone was "absolutely not considering" an IPO.

Private investment funds have pursued public offerings because it allows them to raise money quickly without having to go out to institutional investors on a long and costly fund-raising tour.