THE Hang Seng Index yesterday chalked up its third record in two weeks with a 58.02-point jump to 6,894.9, on rumours of encouraging developments at the Sino-British talks in Beijing and confirmation that a third round of discussions would be held. The buoyant sentiment also saw the index break the 6,900-point mark with an intra-day record of 6,915.19 in frantic late-afternoon trade. The market has gained 143.96 points this week with two rallies sandwiching a day of profit-taking. Brokers said this pattern would probably continue for the next few months, with the index bumpy but on the rise. On the futures exchange, the May index contract jumped 95 points to 6,905. Investors were encouraged by speculation that Chinese negotiators might be willing to separate economic issues from political ones. This would be good news for a financing deal on the Chek Lap Kok airport. ''It was an excellent day,'' said Jardine Fleming salesman and director W.K. Wan. ''People believe a third round of talks wouldn't be necessary if there wasn't something to discuss, so a resolution could be close.'' Another rumour was that mortgage requirements might be relaxed from 70 per cent to 80 per cent of the purchase price. This helped the property sub-index jump 145.46 points to 10,727.6. Sun Hung Kai Properties put 11.28 points on the index with a $1 climb to $36.75, while Cheung Kong and New World added 40 cents each to $26.30 and $20.80, respectively. The index fell on the opening bell to lose 29.24 points to 6,807.64 by 11.15 am, following from Tuesday's profit-taking and on rumours that US funds had started to sell short on the May index contract. Rumours of good news from Beijing then circulated and the index quickly rebounded to 6,871.86 by lunchtime. In the afternoon, the index rose to the intra-day record of 6,915.19 at 3.15 pm before falling back in the last 15 minutes. Brokers said the late fall was partly caused by SHK Securities, which was a big seller of Hongkong Land and Hutchison Whampoa. They added that turnover, which reached $4.88 billion, was restrained because investors had little time during the afternoon session to chase stocks. Hutchison was among the heaviest traded, with turnover of $200.83 million. The stock fell 20 cents to $19. Brokers said there was speculation that Hutchison might make a share or rights placement soon, worth between $5 billion and $6 billion, with mainland parties taking up most of the issue. Cathay Pacific Airways was actively traded for the third day, notching up a turnover of $138.54 million. The stock rose 30 cents to $11 with strong interest from US institutions. Telecommunications firm S. Megga was the only non-blue chip among the top 10 active stocks, with a turnover of $137.98 million. It rose 2.5 cents to $2.45. Among second-and third-line counters, Uniworld attracted the day's highest volume of 401.65 million shares. The stock soared 20.5 per cent, 0.7 cents, to 4.1 cents. Seapower Securities research director Samuel Lau Kwok-leung said red-chip stocks such as China Travel and Guangzhou Investment saw prices jump on anticipation of major transactions. Takeover speculation helped boost Allied Industrial and World Trade Centre Group. Allied Industries edged up two cents to $1.26 on a heavy volume of 68.32 million shares, while World Trade Centre rose 11 cents to $1.34 on 36.92 million shares dealt. Telecommunications manufacturer Team Concepts posted the day's biggest gain, rising 21.2 per cent, 27 cents, to $1.54.