Moody's Investors Service is reviewing whether or not the credit rating agency should adjust ratings downward on tens of billions of dollars worth of commercial mortgage-backed securities to account for increased losses from specially serviced and troubled loans. Analysts may downgrade dozens of classes of CMBS issued by JPMorgan Chase Commercial Services, Morgan Stanley Capital Trust, Wachovia Bank Commercial Mortgage Trust , Lehman Brothers-UBS Commercial Mortgage, Citigroup Commercial Mortgage Trust and Merrill Lynch. Dozens more classes were placed on review for possible downgrade and most of the securities were issued in 2005 and 2006. The ratings agency has been closely monitoring the CMBS classes, as the foreclosure crisis spreads and the aggregate balance of many of loan pools decreases, resulting in interest shortfalls among other problems. Moody's anticipates many of the pools "will continue to experience interest shortfalls because of the high exposure to specially serviced loans." Loans that require special servicing see additional costs, such as workout and liquidation fees, appraisal subordinate entitlement reductions, and extraordinary trust expenses, that impact loan performance, according to analysts. Write to Jason Philyaw.