After weeks of picketing, United Steelworkers at 3M’s Cottage Grove chemicals plant voted to approve a four-year labor contract that will lower some weekend wages and give 3M more say in scheduling shifts.

An estimated 70 percent of the 400 union members at the 763-worker plant voted in favor of the labor contract. The approval comes just two weeks after members voted down a recent 3M proposal.

This week’s vote, however, shifted the dynamic, pointedly asking the steelworkers to either vote for the labor contract or vote to strike.

3M’s new, four-year labor contract will replace a three-year agreement that expired in August. The old contract was extended on a temporary basis while the two sides worked toward a new agreement.

Specific details about the new contract’s wages, hours and schedules were not immediately available Wednesday.

“Both parties have agreed to a four-year contract, and we look forward to our continued relationship with the United Steelworkers,” said 3M spokeswoman Fanna Haile-Selassie in an e-mail. She declined to provide specifics about the contract’s language.