March 13 (Reuters) - BP on Friday issued a revised contract offer to union workers at its Whiting, Indiana, oil refinery after members of the United Steelworkers overwhelmingly rejected what the company had described as its "last, best and final" proposal.

The USW stated that "an unprecedented 94% of union members voted Thursday and 98.3% voted not to accept BP's offer."

BP had presented the union with what it called its final offer last week, and said that it would expire in 10 days.

"This revised offer isn't about penalizing the union or its members for rejecting the offer. It's simply a reflection that certain incentives were contingent on reaching agreement by March 12, 2026," BP said in an employee bulletin released after the vote on Friday.

Under the revised proposal, first-year wage increases would no longer be retroactive to February 1, 2026, instead taking effect from the first full pay period after ratification.

BP also reduced a $7,500 lump-sum payment to $2,500, bringing total lump-sum payments to a range of $2,500 to $10,000.

The company said the revised offer would not have an expiration date.

"More than 98% of our union members voted to reject British Petroleum's last offer, yet less than 24 hours later, the company's response is somehow even worse," said Eric Schultz, president of United Steelworkers Local 7-1.

"BP is obviously not serious about reaching a deal that doesn't include cutting jobs, reducing wages and eliminating bargaining rights," Schultz added.

Schultz said the union would continue to discuss the path forward.

Since the contract expired on January 31, the union has been working under rolling 24-hour extensions of their previous agreement.