Bargaining between Metro Trains and the transport union over pay and conditions is set to drag on with the latest offer from the company likely to be rejected by the Rail, Tram and Bus Union.

Train drivers, authorised officers and station staff have been offered a 3.5 per cent annual pay rise in a new enterprise bargaining agreement sent out on Tuesday by Metro Trains.

Victorian RTBU secretary Luba Grigorovitch says a proposed enterprise bargaining agreement from Metro Trains is likely to be rejected. Credit:AAP

The proposed agreement grants workers a 14 per cent pay rise over four years, or 3.5 per cent per year. The union wants a 6 per cent annual increase over three years.

The rail operator and union have been negotiating a new wage deal since February. The old agreement expired at the end of June.