Property sales last month are estimated to have jumped 20 per cent from December to breach the 9,000 level. Figures compiled by Midland Realty and Centaline Property Agency showed transactions rose to between 9,183 and 9,198. The total value of transactions jumped about 17 per cent to HK$21 billion. The transaction volume almost doubled the 4,645 deals registered in January last year. Midland said the pick-up was due mainly to a 23.3 per cent month-on-month rise in secondary residential transactions to 5,089, the highest monthly volume since September last year. The value of secondary transactions was HK$8.3 billion, up 16.8 per cent from December. There were 2,953 primary residential deals, up 9.7 per cent from the previous month, while their value grew about 10 per cent to HK$9.7 billion, according to Midland. Centaline Property said aggressive marketing efforts by developers and the low interest-rate environment combined to boost primary home sales. Primary transactions documented with the Land Registry last month included 975 units at Metro Harbour View in Tai Kok Tsui, 392 units at Park Central in Tseung Kwan O, 174 units at Sorrento in Kowloon Station and 138 units at Victoria Towers in Tsim Sha Tsui.