The Secretary of the Port Development Board, Tony Clark, is to join the exodus of expatriates from the Government. Mr Clark is to retire on October 12. He will be replaced by Principal Assistant Secretary for Economic Services, Richard Yuen Ming-fai, who has mainly been dealing with telecommunications issues. In order to prepare enough experienced local officers for senior positions, a ceiling has been imposed on the number of expatriate officers at staff grades A and B1. The limit has been set at two and four officers respectively. The move means Mr Clark would have no chance of promotion in the near future. Mr Clark, 55, chose not to renew his contract with the Government. He will stay in Hong Kong until early next year. He said he had not yet decided whether he would join the private sector on his retirement.