The Chinese have seen through a mechanism intended to disguise the fact that in any merger, British Telecommunications Plc would take control of Cable & Wireless Plc. Shares in the latter slipped 10 British pence to 525 pence yesterday after a London Sunday Times story said that China was not at all keen on Hong Kong Telecommunications Ltd passing to a company so closely associated with Britain when British sovereignty over Hong Kong is due to end in June 1997.