A two-day strike by up to 1,200 workers will now go ahead on Sunday and Monday.
A breakthrough could not be found after two days of talks between the union and refinery owners at conciliation service Acas.
A statement from Acas said that although the two sides had not come to an agreement, time had been spent addressing the issue of safety and the integrity of the Grangemouth site during the strike.
A spokesman for the union said: "Unite's negotiators were disappointed with the company's refusal to withdraw controversial pension plans and, therefore, the two-day strike will go ahead."
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Ineos Chief Executive Tom Crotty said: "We have done everything we can to help resolve this dispute.
"Our latest offer to suspend all proposed changes to the existing pension scheme is just another example of us bending over backwards to bring this conflict to an end.
"The plain fact is that the union seems hell bent on pursuing a strike that will cause chaos and disruption for the people of Scotland and across the UK."
However Finance Secretary John Swinney said there should be enough fuel to avoid shortages.
Mr Swinney said: "What we are confident about is that we have taken preparations to make sure that there are ample supplies of petrol and diesel available well into the month of May.
"That's obviously predicated on consumer purchasing patterns remaining as we would normally expect them to be."
He added: "We also have the ability to import fuel into the bargain if we need to support the stocks that we have already within Scotland so the plans are well advanced."
(GK/JM)
