LOBBY group the Coalition for Free Enterprise in Hongkong has broadened its membership and retained Mr Warren Williams, a noted business executive and former president of the American Chamber of Commerce, as a consultant. The coalition attempts to stop perceived unfair competition between government-subsidised organisations and the private sector. Mr Williams said that as well as media companies, members now included a manufacturer, design companies and an association, and it was on the verge of signing a major professional body. The Mass Transit Railway Corp, Productivity Council, Radio Television Hongkong (RTHK) and the Trade Development Council are among the bodies under attack from the coalition. One coalition member is Metro Broadcast Corp, whose managing director Craig Quick said yesterday that RTHK's sponsorship unit was competing with his sales staff but was able to cut rates by half because of its government support, budgeted at $275.8 million this year. Another is Headway Trade Fairs, a major exhibition organiser. Another member is the Asian Sources Media Group. Chairman Merle Hinrichs said the Trade Development Council (TDC), funded through a 0.05 per cent ad valorem duty on imports and exports, was using ''taxpayers' money to compete against private enterprise''. Asian Sources is a magazine publisher that has complained of unfair competition from magazines produced by the TDC, and Mr Hinrichs has been the coalition's most prominent member. He said yesterday the coalition was not merely a vehicle for pursuing his complaint about the TDC, but was concerned with matters of policy. ''The coalition's sole objective is to eliminate unfair competition by government in Hongkong's private sector,'' reads its briefing paper. Government bodies criticised have responded to many of the allegations. Mr Raymond Ng Sek-fai, assistant director of broadcasting at RTHK and manager of its sponsorship unit, said the amount of sponsorship raised by RTHK would be restricted to $9 million next year and was ''totally insignificant'' compared with the territory's total radio advertising spending. Polls had shown that sponsorship was viewed favourably by listeners, he said. Mr William Cheung, a representative of the TDC, said the presence of many business people on its various committees showed ''broad support from the Hongkong business community'' and that the coalition's statements ''contained inaccuracies and misconceptions''. The Mass Transit Railway is under attack because a free publication it offers is the only one distributed in its stations, and for the rates it offers for poster space that the coalition says are lower than could be offered by the private sector. Mr Williams said other members were concerned about the Productivity Council's move into manufacturing and the management of the Hongkong Convention and Exhibition Centre, which is owned by the TDC and which has the TDC as a major customer for its many trade shows. Although he agreed with the Government's stance on most business issues, Mr Williams said: ''There are a few things that are being done that are blatantly naughty, counter-productive and should be stopped.'' The coalition sent a petition to Governor Chris Patten explaining its opinion and it briefed legislative councillors before this month's debate on fair trade.