OSLO - Norwegian offshore workers will likely go on strike on Tuesday in an industrial action that will cut oil and gas output as the negotiating parties have not made progress, the union and the lobby representing oil companies said on Monday.

"As it stands now, there will be a strike tonight," a spokesman for the Norwegian Oil and Gas Association (NOG) told Reuters. "The situation is quite locked ... No talks are scheduled today."

Industrial action will begin at midnight local time (2200 GMT) at three fields - Gudrun, Oseberg South and Oseberg East - and will then expand at three other fields - Kristin, Heidrun and Aasta Hansteen - from midnight on Wednesday.

A seventh field, Tyrihans, will have to shut because its output is processed from Kristin.

By Tuesday, oil output would be cut by 89,000 barrels of oil equivalent per day (boepd) and gas output by 27,500 boepd, or 4.4 mcm per day, Equinor has said.

By Wednesday, a strike would cut the country's gas output by 292,000 barrels of oil equivalent per day, or 13% of output, NOG said on Sunday.

Oil output would be cut by 130,000 barrels per day, the lobby added, corresponding to around 6.5% of Norway's production, according to a Reuters calculation.

"As things stand now, it looks like there will be a strike," Lederne leader Audun Ingvartsen told Reuters.

The Norwegian government has said it was following the conflict "closely". It can intervene to stop a strike if there are exceptional circumstances.

The strike, in which workers are demanding wage hikes to compensate for rising inflation, comes amid high oil and gas prices, with supplies of gas to Europe especially tight after Russian export cutbacks.

Members of the Lederne trade union, who represent senior workers, on Thursday voted down a proposed wage agreement that had been negotiated by companies and union leaders.

Norway's other oil and gas labour unions have accepted the wage deal and will not go on strike.

(Reporting by Gwladys Fouche, Editing by Louise Heavens)