ABOUT 64 per cent of the civil service's 1,376 directorate officers and just over half of all the policy secretaries and department heads are local officers, according to the Secretary for the Civil Service, Mrs Anson Chan Fang On-san. She said the localisation policy had been broadly successful and progress had sped up with the expansion of tertiary education, the widening of opportunities for obtaining professional qualifications locally and the Government's own training schemes. In 1952, the percentage of overseas officers in the civil service was about 4.5 per cent. On January 1 this year it was 1.2 per cent. The percentage of locals taking up senior management and professional posts rose from 70.4 per cent in April 1988 to 78.7 per cent in January this year. ''These figures are expected to increase further in the near future as more and more local officers move up through the ranks of the civil service,'' Mrs Chan said. The police force has also experienced a steady progress in localisation with the proportion of locals taking up positions at assistant commissioner level or above rising from 18.2 per cent in 1988 to 32 per cent last January. Mrs Chan said there was no general target for phasing out all overseas officers. ''Indeed the Joint Declaration and the Basic law make specific provision for the continued employment of overseas officers, with one exception,'' she said. The exception was principal official posts, which must be held by Chinese nationals who are Hongkong residents without foreign right of abode.