CHICAGO--(BUSINESS WIRE)--Fitch Ratings has upgraded two classes and affirmed six classes of LB-UBS Commercial Mortgage Trust commercial mortgage pass-through certificates, series 2004-C6 (LBUBS 2004-C6). A detailed list of rating actions follows at the end of this press release. KEY RATING DRIVERS The upgrades of classes F and G reflect the repayment of 37 loans in the last 12 months, including several loans that were previously in special servicing. No new loans have transferred to special se