NATIONAL Mutual's Conscience Fund, one of the few socially conscious funds authorised for sale in Hongkong, has proven less than successful in attracting investment. The UK-based fund, which avoids investment in brewing and tobacco companies and countries such as South Africa, concentrates its investments in the UK and Europe. Enthusiasm for the fund has undoubtedly been dampened by its poor performance; return on investment amounted to 4.5 per cent over the last five years, and performance fell by 8.3 per cent between February 1992 and the same month this year. Mr Edward Lim, manager of marketing at National Mutual in Hongkong, noted that investment was discouraged by UK regulations which made investment in the fund both more complicated and more costly. One major problem was difference in the spread on investment. The fund advertises a spread of 5.75 per cent, but Mr Lim said it was closer to seven per cent because of the regulations. Some, however, believe there is a more general problem in trying to market such funds here. Mr Stewart Aldcroft, a director at Wardley International Management, explained that ''while the objectives are very good, they are not something Asians are familiar with'', adding that Wardley had no plans to offer such a fund. ''Frankly,'' he said, ''there is a complete lack of interest in ethically based funds''. While public campaigns may spark interest in the environment and health, there seems little optimism that it will inspire private investment from people in Hongkong, at least in the near future.