"The worst is yet to come"

A lot of commercial real estate loans were also temporarily interest-only, and they too are going to start recasting.

Loans that postpone principal payments had become the norm by the time the commercial-mortgage bond market peaked two years ago, said Frank Innaurato, managing director of analytical services at Realpoint LLC, a Horsham, Pennsylvania-based credit- rating service.

“The proliferation of interest-only loans was symptomatic of the loose underwriting standards of that time,” Innaurato said. “Borrowers were taking advantage of the best terms possible.”

Property owners turned to Wall Street to finance office towers, apartment complexes and hotels as banks bundled the debt and sold it to investors. A record $230 billion in commercial mortgage-backed securities were sold in 2007, up from $93.3 billion in 2004, according to Morgan Stanley data. About $750 billion of such debt is outstanding, bank data show.