Niksic (MINA-BUSINESS) - Workers of the Trebjesa brewery will stage a one-hour strike of warning on Monday because of the management#s rejection to sign a specific collective agreement, the company#s trade union said. If no agreement is reached, the workers will organise a general strike on May 20. The dispute over the collective agreement has been going on for months as the workers want higher salaries and different criteria to determine the wages, due to an increased beer production. The management of the brewery said it could offer no salary increase after the wages rose 18.5 percent in January.