Almost 35,000 employees had been scheduled to go on strike if no agreement was found, and a conflict could eventually have escalated to include more than 200,000 workers.

A strike would immediately have idled aluminium smelters, fertiliser plants, ship yards and chemical factories, and could eventually have been extended to hit output of oil and gas, unions said ahead of the talks.

The deal remains subject to a vote by labour union members, mediator Nils Dalseide told reporters.

The agreement gives workers an estimated average pay rise of 2.8 percent in 2018, slightly more than the maximum 2.7 percent employers had said they were willing to pay.

Some adjustments were also made to pensions for low-paid workers, although a union demand for more wide-ranging pension reform was rejected and will be subject to a future government study.

A separate claim of compensation for travel-related expenses was resolved, unions said.

(Reporting by Terje Solsvik, editing by Gwladys Fouche)