UPDATE 1-Ratings agency cautious on office owner Maguire

NEW YORK Aug 12 (Reuters) - Southern California office building owner Maguire Properties Inc (MPG.N) may return more buildings to lenders after walking away from seven properties because it could not pay the mortgages, rating agency Realpoint said on Wednesday.

"Realpoint has added concern that more Maguire-sponsored properties may be at risk of the same fate following the completion of an overall evaluation of the company's real estate portfolio," Realpoint said in a note.

Five of the seven properties were part of a package of 24 buildings that Maguire bought for $3.1 billion from Blackstone Group at the height of the commercial real estate boom in 2007. Blackstone flipped several portfolios of office buildings immediately after it bought Equity Office, then the largest U.S. office landlord.

The credit crisis has torpedoed some of those Equity Office investments, including the $7 billion purchase of New York Properties that Manhattan developer Harry Macklowe bought from Blackstone. Within a year of the purchase, Macklowe, like Maguire, returned the keys to its lender, Deutsche Bank.

Six of the properties were put up as collateral for loans in existing commercial mortgage-backed securities (CMBS) transactions, said Realpoint, which those bonds.

Mortgages on Maguire buildings are contained in 33 CMBS loans totaling about $4.6 billion on 29 commercial properties in 24 CMBS deals, Realpoint said.

Maguire also has suffered from the residential real estate bust after some of its top tenants, including mortgage lenders New Century Financial Corp and Ameriquest, went out of business.

At the end of the second quarter, Maguire, a Los Angeles-based real estate investment trust, had $4.9 billion in liabilities but total unrestricted cash of only $81 million and negative net worth of $418 million. It had $671 million of debt maturing in 2010.

"It is doubtful that these loans can be repaid with current funds," Realpoint said in a note.

Maguire could not immediately be reached for comment.

Shares of Maguire, which had been up as much as 17 percent Wednesday morning slid after Realpoint's warning to close at $1.09, up 10 percent on the New York Stock Exchange. (Reporting by Ilaina Jonas. Editing by Robert MacMillan)