Detroit ? Chrysler LLC cleared another major obstacle to its survival Sunday when it reached a tentative deal on concessions with the United Auto Workers union, helping it move closer to inking a vital alliance with Italy’s Fiat Group SpA.

The troubled automaker is just days away from a Thursday U.S. government deadline to gain concessions from its unions and debtholders and link up with Fiat or face almost certain liquidation. White House economic adviser Larry Summers said Sunday the Obama administration is holding out hope that Chrysler can avoid bankruptcy court.

The UAW late Sunday called the concessions painful but said the deal takes advantage of the Obama administration giving Chrysler and its workers a second chance. The administration in February rejected Chrysler’s restructuring plan and gave the Auburn Hills, Mich., automaker until April 30 to make further cuts and arrange to take on Fiat as a partner.

The UAW agreement is seen as a key piece of pulling Chrysler’s plan together, and it’s noteworthy that the UAW said Fiat was involved in the deal.