The vote against the tentative agreement by union members at a Detroit-area facility Sunday was the fourth rejection by a large assembly plant since voting began Thursday, The Detroit News reported.

With about one-third of the locals reporting results, at least six, representing more than 11,000 workers, voted against the deal, the Detroit newspaper reported. At least eight locals, representing 6,500 workers, approved it.

About 45,000 Chrysler workers are eligible to vote on the contract and a majority of those must approve it for ratification. If it isn't ratified, negotiators would have to return to the bargaining table.

Voting at various UAW locals continues through Wednesday.

Union sources told the newspaper two provisions of the UAW-Chrysler agreement are proving to be particularly troublesome for union members: A two-tier wage system in which new hires for jobs not directly tied to vehicle assembly would be paid less and the lack of specific product commitments for Chrysler plants.

The deal includes the promise of up to $15 billion in new domestic investment, offers workers a $3,000 bonus and creates a union-controlled trust fund to cover healthcare costs for retirees.