A RECORD number of former Hong Kong emigrants in top managerial positions have returned in the past year, indicating that the brain drain is slowing down. A survey conducted by the Institute of Personnel Management (IPM) showed that the number of returning senior executives amounted to 50 per cent of the tally of those emigrating in this category in the 12-month period ending June 1993. Hong Kong has suffered serious brain drain in the past few years, especially after the June 4 Tiananmen Square massacre in 1989. The survey recorded that despite a total of 132 senior executives emigrating in the period, as many as 63 top managers who had emigrated earlier had returned to Hong Kong from July 1992 to June 1993. This represented an unprecedented high returning rate of 47.7 per cent for the class, compared with 28.1 per cent and 19.6 per cent in 1992 and 1991 respectively. In general, an overall higher returning rate of 16.6 per cent was also recorded as compared to 11.1 per cent in the previous 12-month period. The return rate was around eight per cent in years before 1990. Employees in the engineering and the public utilities sector currently have a returning rate of 43.6 and 28.8 per cent respectively. The rising trend was due to a combination of the buoyant Hong Kong economy, alongside southern China, and the still stagnant economy in most Western countries, said the IPM's past president Patrick Maule. Mr Maule said the salaries offered in Hong Kong were already among the most competitive in the world. He said senior executives could earn 50 per cent more in Hong Kong than in places like Canada and Australia, even without taking into account the much higher income tax rates in the Western countries. He said the territory had been experiencing a double-digit salary increase in the past few years, which pushed salaries of those at managerial levels within the high range of $300,000 to $800,000 a year. ''But in places like Canada and the United States, salaries increase at a rate of one to two per cent,'' he said. ''Forgetting politics, forgetting confidence, you've got a very full economy,'' he said. ''This coming year, we are still talking around 9.5 to 10 per cent salary increase.'' But Mr Maule envisaged that most of the returnees might have a hard time in Hong Kong as they had sold their properties when they left Hong Kong. and found it hard to buy their own flats. ''They haven't been able to save money and they even lose out on properties they bought in Canada and Australia,'' he said.