When the twin 100-story towers and two nine-story office buildings were net-leased in July for $3.2 billion to a joint venture consisting of Silverstein Properties and Westfield America, GMAC provided the $563-million first mortgage. Officials of the Horsham, PA-based company also committed to a $200-million mezzanine loan for future capital improvements, which never commenced.

"The insurance required in connection with GMAC Commercial Mortgage's financing does not exclude coverage for acts of terrorism (and includes damage caused by aircrafts)," the company says in a statement. "The insurance is from a consortium of 22 large and well-rated insurers."

GMAC Commercial Mortgage adds it gave notice Wednesday of its status as mortgagee and loss payee and asked its insurance companies when it can expect payment of claims.