BUENOS AIRES - Pressure grew on Friday for a resolution to wage talks between exporters and striking crushers in Argentina’s Rosario grains hub, with another powerful union threatening to launch its own industrial action on Monday that would paralyze exports. The strike by the Soyoil Workers Federation, which represents about 20 percent of crushing workers in the world’s No. 1 soyoil and soymeal exporter, began more than three weeks ago at the peak of an expected record harvest. “On Monday there’s no turning back,” union head Daniel Yofra said by telephone. Yofra said he remained optimistic a deal would be struck, but there were no indications of any impending agreement. Late last week Yofra said that a deal had been reached with employers for a 36 percent wage hike, but the government opposed the accord. With the talks poised to continue later into Friday, Andres Alcaraz, a spokesman for the CIARA chamber, which groups producers and exporters of grains, declined to comment. On Thursday, he too had said he was “cautiously optimistic” of an agreement. An official at the labour ministry said he had no update on progress in the talks. Tough pay talks and strikes are common in Argentina at this time of year, as workers negotiate wages in line with one of the world’s highest rates of inflation. Prices surged about 35 percent in 2014, according to private estimates. The government acts as mediator in the negotiations but has significant leverage over the final outcome. Earlier this month, the economy ministry agreed a 27 percent pay rise for two government-allied unions. The crushers’ strike initially only impacted smaller ports in Rosario’s southern districts, but since Tuesday the union has been blocking some larger terminals in the north, such as those run by Bunge Ltd and Cargill Inc. The local Chamber of Port and Maritime Activities said the loading of 41 vessels had so far been delayed since Tuesday. That relatively small number of ships could however accelerate higher if the local branch of the muscular CGT union, which accounts quality control and dock workers among its members, proceeds with its strike on Monday. A CGT official said its strike action would definitely proceed if there was no deal with the crushers.