Hong Kong's economy will lose about $78 billion between next year and 2011 if container terminals 10 and 11 are not built, Port Development Board (PDB) secretary Tony Clark says. Besides the urgent need for the delayed container terminal 9, the territory needed a new port that had been planned at Tsing Chau Tsai, which included construction of terminals 10 and 11, Mr Clark said. Consultants recommended in March 1993 that 17 berths should be opened between next year and 2011 on linked artificial islands forming two port basins on Lantau Island, linked by a transport corridor, he said. 'Detailed design work is well under way for CT10 and 11. The estimated cost of building them is in the order of $28 billion, of which some $9 billion will be borne by the Government,' Mr Clark told delegates at a Hong Kong Institution of Engineers and Hong Kong Institute of Planners conference. Hong Kong also needed to start detailed planning of CT12, as the first berth of that terminal was likely to be needed during the early years of the next century, he said.