DETROIT (AP) — Contract talks aimed at ending a 21-day strike by the United Auto Workers against General Motors have taken a turn for the worse, hitting a big snag over product commitments for U.S. factories, a union official wrote in an email to members. The letter from UAW Vice President Terry Dittes casts doubt on whether there will be a quick settlement in the contract dispute, which sent 49,000 workers to the picket lines on Sept. 16, crippling GM's factories. Dittes' letter says the union presented a proposal to the company Saturday. He said GM responded Sunday morning by reverting back to an offer that had been rejected and made few changes. The company's proposal did nothing to address a host of items, Dittes wrote, specifying job security for members during the term of the four-year contract. Advertisement Advertise with NZME.