Calum McLean, chairman of Ineos Grangemouth, has said that there is a 15-20 year future for the petrochemical plant.
He said there had been a "change of mind" by the Unite union and that the firm had received a "very clear message from the employees".
He added that the company plans to invest a further £300 million in the plant and that "redundancies will be very limited".
Grangemouth owners Ineos are in last ditch talks with the workers' union, but the workforce is just one of the problems facing the plant.
Thousands of jobs are under threat after a dispute over conditions led to a shock decision to close the petrochemical site in Grangemouth.