RENTS for prime offices have shown a healthy recovery with an average increase of 11.3 per cent last year. The bulk of the rise was achieved in the past six months, during which rents went up 10.3 per cent, according to the latest office market review commissioned by City Property Consultants. Last month, rents edged up 0.9 per cent to $42.39 a square foot on the back of stable leasing activities. The review also noted that office vacancy rate had dropped sharply from a high of 6.2 per cent in February to a low of 2.4 per cent last month. The uptrend in rentals confirms the sustained demand for quality offices in the territory, which is still considered a popular destination for foreign companies setting up operations in Asia. Office rentals had dropped since April 1989 by as much as 30 per cent before reaching the bottom early last year. They started to recover in May. Office rentals in Hongkong are still the highest after Tokyo. The City Properties report covers 76 selected prime office buildings involving a net floor area of about 21.95 million sq ft. It said office rents in Central and Admiralty jumped 11.2 per cent last year, and 10.9 per cent in the past six months. Last month alone they rose 1.1 per cent to average $46.80 a square foot. The average rental in Wan Chai and Causeway Bay was up a slight 0.6 per cent to $34.95 last month, nine per cent for the past six months and 11.2 per cent for the year. The vacancy rate in Central and Admiralty fell to 2.3 per cent, or 311,000 sq ft of unoccupied space. The rate in Wan Chai and Causeway Bay stood at 2.8 per cent, or 225,500 sq ft. Rentals at Exchange Square stood at $57 - the highest in the territory - while Gloucester Tower and Edinburgh Tower in the Landmark commanded a monthly rate of $54. Rents for offices in Nine Queen's Road Central, Central Building and Prince's Building were $53, $52.50 and $50, respectively. Rentals in Pacific Place were in the range of $44 to $45, while United Centre had a rate of $38.06 and Sing Pao Centre $34.69. In Wan Chai, Convention Plaza reported a rate of $40.19, while Dah Sing Financial Centre recorded $40.66. The rates in Great Eagle Centre, Causeway Bay Plaza and Windsor House were $37.78, $36.50 and $34.12, respectively.