Chrysler headquarters are shown in Auburn Hills, Mich. , Monday, April 27, 2009. Chrysler LLC cleared another major obstacle to its survival Sunday when it reached a tentative deal for concessions with the United Auto Workers union. The troubled automaker is just days from a June 1, U.S. government deadline to gain concessions from its unions and debtholders and form an alliance with Italy's Fiat Group SpA or face almost certain liquidation.