THIN overseas buying bumped the Hang Seng Index to another record finish after see-saw trading. Calming down from Tuesday's rally, the index edged up 13.66 points or 0.14 per cent to 9,750.23 on a trimmed-down turnover of $6.46 billion. ''Local investors stayed on the sidelines, with a little overseas buying,'' said Baring Securities director James Osborn. ''It was very quiet.'' Americans were among the stronger buying forces which wiped off initial losses due to profit-taking. Mixed sentiment resulted in a tug-of-war between buyers and sellers, although caution was the order of the day, especially for local investors. GK Goh Securities dealing manager Bobby Ho said locals were more hesitant about the Joint Liaison Group meeting in London and Sino-British political relations generally. ''On the Sino-British dispute, there is a general feeling that we have not seen the full extent of the Chinese reaction yet,'' said Nomura Research Institute general manager Clive Weedon. Other concerns on investors' mind were US interest rate movements as figures last week suggested a better-than-expected growth in the American economy could fuel an increase. Investors were also concerned over the development of China's economy, he said. ''The bulls and bears can have very different views on these [factors],'' said Mr Weedon. He said most investors were bullish on the long-term prospects of local stocks. ''What we've seen [in yesterday's slight gain] is just a drop in the ocean. The underlying trend will still remain firmly upward,'' he said. Salomon Brothers vice-president David Williamson said there was continuing strong demand for local equities despite political uncertainties. Yesterday's turnover was good enough for a December day when ''a lot of fund managers close their books and go away for Christmas holiday'', said Mr Weedon. After moderate buying in London overnight, the market opened at 9,757, up 20 points from the Tuesday close. Continued buying momentum rapidly sent the index shooting to the day's peak of 9,792.97 in the first 15 minutes of trading. But just as swiftly it nose-dived to the day's low of 9,644.81 in the next half hour. ''There was intra-day profit-taking. But equally we saw solid support there,'' said Mr Weedon. The index then bounced back to conclude the morning session at 9,738.61. Trading in the afternoon hardly saw much excitement, with the index swinging up and down within a narrow 20-point range. In the futures market, the December contract strengthened 45 points to close at 9,725, a 25.22-point discount to the spot index. Estimated volume for December futures was 11,930 contracts, compared with total market activity of 12,214 lots. Confirmed total volume for Tuesday was 19,905, with open interest confirmed at 34,296. Bulls started to roll their long positions in December over to January. ''The options market was generally bullish,'' said Vivian Ting of Jardine Fleming. Of the Hang Seng sectoral sub-indexes, only utilities lost ground, off 14.17 points to 11,582.23. Among individual counters, Far East Hotels and Entertainment fared best on rekindled rumours that Li Ka-shing would either acquire the company or some of its assets. It gained 30 cents or 18.3 per cent to $1.94 on turnover of $78.41 million. Henderson Investment was the ninth-biggest loser on the heels of the announcement of its $2 billion placement It eased 25 cents or 3.5 per cent to $6.90 on turnover of $54.73 million. HSBC Holdings was the busiest stock and the top index mover, contributing 7.17 points of the index gain. It added 50 cents to $92, as shares worth $491.61 million were traded.