June 28 (Bloomberg) -- Carlyle Group, the buyout firm run by David Rubenstein, postponed a planned $415 million initial public offering of a fund that invests in bonds backed by mortgages after a slump in the U.S. subprime market.

Carlyle is preparing a revised timetable for the sale, it said in a statement today. The Washington-based firm planned to use most of the money from the IPO to buy AAA-rated residential mortgage-backed securities. The fund also targeted loans, high- yield bonds, and collateralized debt obligations.

Rising interest rates in the U.S. have fueled a surge in defaults on subprime home loans used by borrowers with poor credit histories. Investments backed by subprime mortgages are at the center of this month's losses by two hedge funds run by Bear Stearns Cos., the No. 5 U.S. securities firm. Investors are now cutting back on riskier assets.

``Carlyle's fund looked very similar to the Bear Stearns hedge fund,'' said Toby Nangle, who helps manage $45 billion in assets at Baring Investment Services in London. ``They were unlucky with the timing.''

New York-based Bear Stearns's funds speculated in highly rated CDOs, which are securities backed by bonds, loans, derivatives and other CDOs. The securities were hurt by a surge in subprime defaults in March and April.

Caliber, Queen's Walk

Caliber Global Investment Ltd., a $908 million fund managed by Cambridge Place Investment Management LLP, said today it will close after losses on U.S. subprime debt. Queen's Walk Investment Ltd., a fund managed by London-based hedge fund manager Cheyne Capital Management Ltd., said June 25 it had a $91 million loss in the year to March 31 in part because of subprime.

Emma Thorpe, a spokeswoman for Carlyle in London, had no immediate comment.

Carlyle tried to follow Kohlberg Kravis Roberts & Co. and Apollo Management LP in selling shares in funds listed in Amsterdam. Shares of Blackstone Group LP, manager of the world's second-biggest buyout fund, are trading below the price set in their IPO on June 22.

Carlyle hired John Stomber, a former managing director of Cerberus Capital Management LP, to run the mortgage fund. It planned to add the money raised in the IPO to a $590 million pool raised last year. The firm planned to use loans to buy assets worth as much $17.3 billion, according to the fund's prospectus. More than 95 percent was to be invested in assets rated AAA by Standard & Poor's, the document shows.

Citigroup Inc., JPMorgan Chase & Co., Bear Stearns, Lehman Brothers Holdings Inc., Goldman Sachs Group Inc. and Deutsche Bank AG are managing the sale for Carlyle.

Carlyle is considering a separate IPO of the whole private- equity firm, Dow Jones Newswires reported yesterday, citing Jason Lee, the firm's head of Asia real estate.

To contact the reporter on this story: Edward Evans in London at at eevans3@bloomberg.net.

Last Updated: June 28, 2007 07:32 EDT