INTEREST in Britain is holding up well, with agents reporting about 30 sales from one Hongkong exhibition last week. Regent on the River, a major luxury residential development, close to Chelsea Harbour in London, is being marketed by Richard Ellis in conjunction with Cluttons in the territory. ''We've sold about 30 units, ranging from flats of 1,200 square feet to two penthouses of more than 2,300 square feet,'' said Mr Chris Thrift, a director of Richard Ellis. Of those, 25 had been purchased by Hongkong Chinese and the remainder by expatriates. The exhibition, held at the Hilton, had finished but, due to the level of interest, had been set up for another 10 days in the boardroom of the Richard Ellis office in the Bank of China Tower. ''We're expecting to sell between five and 10 more units in Hongkong,'' Mr Thrift predicted. Apartments sold so far have reaped GBP6.5 million, with individual flats ranging in price from GBP160,000 for smaller units to GBP475,000 for the penthouses. In tandem with the exhibition, the agents arranged for Matheson PFC to be on hand to provide information about a wide range of financial services, including mortgages for interested buyers. ''Mathesons were representing about 10 different banks and building societies and half those interested went for endowment packages rather than straight repayment mortgages,'' said Mr Thrift. ''Strong as interest has been shown here in Hongkong, we are very interested to see what happens in Singapore and Kuala Lumpur where the exhibition goes next. ''We expect to be even busier there.''