Unite said the company made the move despite recording an 8% increase in net profits during 2020, while its annual report said the division responsible for its Tyne and Wear operations brought in a “record 1.46 billion Swiss francs (£1.2 billion) in 2020”.
The workers voted in favour of the deal, which includes a £750 tax-free payment for staff to transfer from weekly to monthly wages and a guaranteed pay increase for 2022.
Unite regional coordinating officer Suzanne Reid said: “This pay victory is a result of our members’ rock-solid collective action.
"Without strong union organisation in a workplace, results like this are simply not possible, which is why it pays to join Unite.
“All industrial action has been called off as the pay offer has been accepted.
"Unite looks forward to working productively with Stadler now that this dispute has ended.”
Rob Baxter, managing director of Stadler Rail Service UK, said: “Working closely with our union partners, we are very pleased to have resolved this dispute and forged an agreement that suits all parties involved.
“We look forward to continued close collaboration with union colleagues for the benefit of our staff.
"Stadler is at a very exciting stage in the north east, with new trains being manufactured for the Tyne and Wear Metro, and a new state-of-the-art depot being built at Gosforth to accommodate them.
"These activities present many opportunities for employees, enrich local communities and support economic growth in the region.”