THE Hang Seng Index continued its steady slide yesterday, but brokers say it may have touched bottom as bargain-hunters start to pick up cheap stock. The index fell 9.69 points to 6,750.33 on modest turnover of $2.51 billion. An encouraging sign was a mini-rally during the final 30 minutes of trading, pointing to a possible strong start to trading next week. Nikko Securities research director Peter Liu said speculation that vice-Premier Zhu Rongji would replace the ailing Premier Li Peng had provided the market with a late boost by reducing selling pressure that had prevailed throughout the day. He said stock prices had firmed because Hongkong institutions, which were quite liquid, had started to buy blue-chip stocks. Baring Securities director James Osborn said there was heavy late-trading interest in Cheung Kong, China Light and Power and Swire Pacific. Cheung Kong gained 10 cents to $24.50 and Swire Pacific was up 25 cents to $36.25, while China Light dropped $1.25 to $37.50. Brokers said China Light's decline was due to heavy selling as investors moved to other sectors. A recent research report issued by Merrill Lynch recommended China Light as a buy due to strong profits from its property portfolio. The US investment house described China Light as one of the few companies in the world with ''defensive'' and ''aggressive'' components in one stock - defensive because of its utility earnings and aggressive because of expected profits from property redevelopment projects, China joint ventures and electricity sales to China. Based on 1994 financial year earnings projections, Merrill Lynch has a 12-month target of $52.40 a share. The July index futures was up 32 points to 6,794, closing at a 44-point premium to the cash market. World International climbed 20 cents to $9.15 after it surpassed analysts' estimates by announcing a 50 per cent jump in profits to $1.46 billion for the year ended March 31. Guoco Group was unchanged at $20.30 despite heavy speculation, confirmed after the market closed, that it would buy Overseas Trust Bank from the Hongkong Government. Tsingtao Brewery, which hit the market with a splash last week, was unchanged at $3.475. In a recent research report, Sun Hung Kai Securities said it was a strong buy because of promising long-term profit prospects. Sun Hung Kai said Tsingtao would benefit from an increase in output capacity to 700,000 tonnes per year from 250,000 tonnes by 1995 and foreign currency income that allowed it to hedge against yuan fluctuations. Peregrine sales director Chris Malpass said the market had been depressed because of negative press surrounding Shanghai Petrochemical, the largest of the nine state-owned enterprises to be listed in Hongkong. He said strong interest in the United States in Shanghai Petrochemical had provided retail investors in Hongkong with some encouragement and, as a result, created support for red-chip shares such as CITIC Pacific, Kader Investment and Continental Mariner. Peregrine was co-sponsor and lead manager of Shanghai Petrochemical's $2.9 billion issue. Television Broadcasts climbed 30 cents to $20.50 after announcing on Thursday it was leading a consortium injecting US$290 million into the regional satellite television industry. A Lehman Brothers report said the move would benefit TVB's programme licensing business, which generates $250 million in annual revenue. It said TVB's role as a producer and distributor of Chinese-language software gave it an advantage over other potential satellite players. Mandarin Dragon and Ong Holdings were the only two non-index stocks to rank among the 10 most-heavily traded. Mandarin Dragon was up 14 cents to $1.69 while mainland-controlled Ong Holdings jumped 13.7 per cent, 75 cents, to $6.20.