SAN FRANCISCO (MarketWatch) -- The Treasury Department is preparing a Chapter 11 bankruptcy filing for Chrysler LLC that could come as early as next week, The New York Times reported Thursday on its Web site, citing people close to the situation. Union pensions and retiree health care benefits will be protected under the filing, according to the Times. Also, the Times reported that Italian automaker Fiat would complete its alliance with Chrysler during the bankruptcy.