Kia Motors Corp.’s unionized workers have rejected a second tentative wage and shift-change agreement reached Sept. 9.

The result comes as a surprise to Kia officials, who suspect last week’s worker rejection of a similar labor agreement with Hyundai Motor Co. Ltd. may have influenced union recommendations, a source tells Ward’s.

No vote count is available yet, but a majority have rejected the deal, the source says. Management plans to issue an announcement when the final vote tally is in.

There will be no immediate meetings on the matter as workers prepare for South Korea’s Thanksgiving holiday Friday. They do not return to work until Sept. 18.

A Hyundai spokesman says no labor talks are scheduled. Unionized workers struck the auto maker for 12 hours Wednesday and Thursday, and the day shift will strike for four hours Friday.