ABOUT 300 crane operators at a Kwai Chung container terminal yesterday staged an 11-hour strike in protest against a new shift system which they say reduces their rest periods. They began action yesterday after Modern Terminals fired two of their representatives following talks with management on Saturday night. The new roster, carried out from this month, allows the operators a one-hour break after two hours' work. This contrasts with the old system under which they were allowed two hours' break after working for two hours. But representative Leung Yiu-kai said: ''We are sometimes asked to work three hours but take only 45-minute breaks. The terminal is too busy and the company is using the new system to strip away our rest time.'' Mr Leung and another representative put their complaints to the management on Saturday night and called a work-to-rule. They were then sacked. About 300 workers, angered by the move, staged a strike from 7 am yesterday, pressing the management to let the two representatives return to work and review the new shift arrangement. During the stoppage, loading and unloading of containers came to a halt, but the company said operations had not been seriously hit because Sunday was not a busy day. The Labour Department began mediation at 3 pm. After three hours of negotiations, the workers called off their action. The company agreed to reinstate the two representatives and meet to discuss the shift system. The company's terminal operation division general manager, Andrew Milliken, said the system was aimed at improving efficiency. ''It was implemented after five months of consultation and study,'' he said.