Fitch Ratings has handed MetLife, the largest U.S. life insurer, a downgrade to A from A+ on potential losses tied to commercial real estate investments, following in the footsteps of similar actions by Moody’s Investors Service and Standard & Poor’s last year. MetLife, which holds $50 billion in commercial real estate loans and commercial mortgage-backed securities, is expected to post a loss of between $2.2 billion and $2.6 billion for the five quarters that will end in December 2010, Fitch said. MetLife posted profits in 2008 as the market turned sour by using derivatives, but lost $2.57 billion in losses during the first three quarters of 2009. U.S. life insurers, with more than $450 billion in commercial holdings, have yet to see the worst of the commercial real estate fallout, said Andrew Davidson, Fitch’s senior director. Davidson said losses on those holdings, like apartment buildings, offices and shopping malls, will come into view over the next six months, threatening another $15 billion in losses.