Judge Harold Greene, charged with overseeing the working out of his antit-trust settlement with AT&T Co that broke up the Bell system, has told Nynex Corp firmly that it may not bypass the Justice Department and go straight to him for a waiver on the rules that bar the Bells from offering long-distance service. He has told the New York and New England phone company that it must await a Justice Department ruling on its request for permission to hold the US end of Cable & Wireless Plc’s PTAT-1 transatlantic fibre optic cable. Cables says that while it is actively seeking another partner for the US end of the cable, laying of which is well under way, it will consider Nynex again if it can get the clearance.