In an effort to standardize its commercial mortgage-backed security rating criteria, Standard & Poors plans to establish a single, all-around framework for rating U.S. and Canadian CMBS transactions. The credit rating agency is seeking comment on proposed criteria for structuring a new CMBS rating framework, which would be used to evaluate stand-alone, large loan and conduit/fusion CMBS transactions. Based on a representative sample of CMBS deals, a modest, limited impact on ratings may be expected on 25 percent of rated CMBS tranches, S&P said. The proposed criteria generally assume a...