MOVES by Hongkong Bank and Hang Seng Bank to curb property speculation, coupled with worse-than-expected interim results from Cathay Pacific, knocked 62.1 points off the Hang Seng Index, which closed at 7,265.58 yesterday. Despite the movement in the index, turnover was a modest $3.72 billion, almost the same as Tuesday's, as uncertainty undermined confidence and kept some major investors on the sidelines. Barclays de Zoete Wedd sales manager Nial Gooding said: ''There was further weakness in the market as the US warned that it may go tough on China on trade and that they were unimpressed with their handling of Mr Han Dongfang.'' The August index futures fell 12 points, on 6,292 contracts, to 7,280, a 15 point premium to the cash market. Total market volume was 12,083 contracts while the open interest fell 141 to 19,859. The market opened to brisk trading for the first two hours and started to fall just before the market closed for the morning. When it re-opened, trading remained flat for an hour and a half until news of Cathay Pacific's interim results came through. HSBC Holdings and Hang Seng Bank on Tuesday detailed moves to crack down on property speculation by tightening credit. HSBC Holdings fell $1 to $80.50 while Hang Seng Bank lost $1 to $54. Combined they took 25.54 points off the Hang Seng Index. The new regulations would include a higher early redemption penalty and looking at the monthly income of borrowers, not guarantors. Sun Hung Kai Securities research director Percy Au-Young said: ''Although the banks had said that their latest policy was to rectify speculation in the property sector, it would appear to us that the banks' mortgage business is going to slow down.'' Property stocks were also hit. Sun Hung Kai Properties fell $1.25 to $36.25 while Henderson Land dropped 30 cents to $20.50. Cheung Kong declined 20 cents to $27.70 while New World Development fell 20 cents to $19.50. Mr Au-Young said that investors were worried that the latest bank curbs would affect property developers, particularly those with residential projects. ''Developers now cannot rely on pre-sale proceeds to finance projects as the banks have announced that buyers who wish to buy units which will not be completed for six months or more will not be able to obtain pre-sale mortgages,'' he said. The property and finance sector were the weakest performers yesterday of the Hang Seng sub-indices, with the finance sector dropping 99.93 points, 1.39 per cent, to 7,083.47 while the property sector fell 121.62 points, 1.1 per cent to 11,114.88. Utilities stood firm, relatively unchanged at 8,570.87. Conglomerates and industrials slipped 45.69 points, 0.83 per cent, to 5,479.51 as Cathay Pacific and its parent lost ground. Cathay Pacific fell 40 cents to $10 while Swire Pacific fell $1.25 to $37. The airline reported a 45.9 per cent drop in net profit for the first half of 1993 to $681 million, compared with its previous year's interim profits of $1.26 billion. Mr Gooding said that Cathay's results were much worse than anyone had expected. ''Although the company had warned the market to expect bad results, its margins came under more pressure than anticipated,'' he said. Kleinwort Benson assistant director Tony Edwards said Cathay's poor results had surprised the market and in turn had a knock-on effect on its parent, Swire Pacific. Jardine Matheson, another hong stock, fell $1 to $57.50. China Light and Power gained 25 cents to $41.25 while Hongkong Telecom was unchanged at $11.80. Mr Gooding said that the market had opened strongly on the back of overseas and local buying of utilities stock. Baring Securities associate director James Slade said that people were moving out of property stocks into second-line counters in the light of the recent bank announcements. Four Seas Mercantile Holdings, which made its debut on the stock exchange yesterday, was the fourth heaviest traded stock on a turnover of $226.23 million. It closed at $2.20 per share, a 120 per cent increase over its offer price of $1.