AS the Hang Seng Index flirts with 10,000, investors around the world are asking themselves if the gravity-defying index can turn in another stellar performance next year. The index has ranked at the forefront of world markets over the past three years. But many brokers believe further signs of trouble in China's rampant economy and the threat of a rise in interest rates will leave the market at the end of 1994 little better of than at the end of this year. Forecasts culled from seven blue-chip brokerages in Hong Kong reveal year-end 1994 forecasts ranging from as low as 9,264 to a high of 12,000. Estimates at the low end are not as bearish as face value suggests: the index is broadly expected to reach 12,000 or even beyond during the course of the year, but the dual threat of swelling interest rates and a new round of austerity measures in China are forecast to nibble into gains over the second half. Earnings growth is expected to remain robust. Most brokerages are looking for a lift in corporate profits of 17 per cent to 18 per cent, with the most optimistic forecasting 19 per cent growth. This compares with 17 per cent this year and 23 per cent last year. Jardine Fleming Brokerage head of research Alex Ho, who is looking for a year high of 12,500, reckons 1994 is a very hard year to call. He said: ''There is the issue of what exactly the Chinese economy is doing, and also the issue of how interest rates go up. if interest rates go up significantly, and then inflation falls significantly, that could affect property market valuations.'' Over-heating in the Chinese economy - an issue addressed and then sidelined by Beijing - stands to be further complicated by the issue of succession. The big wild card is still that when Deng Xiaoping dies, the transition to new leadership may be bumpy and the economy stands to be a main victim. Hong Kong's market is also in thrall to the United States: any move by the administration there to lift interest rates will hit local stocks, as one of the key engines for growth in recent years has been low interest rates, which have encouraged investment and fuelled liquidity. One head of research noted: ''The American interest rate cycle is trending up towards the second half of next year. It probably won't be that significant, but it will trend upwards.'' This is a potentially stronger threat fundamentally than failure to rein in spending across the border, as right now most major listed companies still derive only a fraction of their earnings from the China market. This equation is not expected to changeuntil the latter half of the decade. Favourite stock tips for the new year include investment property companies and selected conglomerates. Cheung Kong, Hutchison, Swire Pacific, Hong Kong Telecom and this year's run-away star TVB all feature in next year's recommendations. S.G. Warburg is also looking at Shanghai Petrochemical and retailers such as Dickson Concepts. Brokers are divided on the driving force behind growth next year: there are those who say it will still be a property-fuelled market, others are still touting the finance sector. S.G. Warburg's head of Hong Kong research, Danny Truell, who is looking for the index to be at 10,000 at the end of the year after a mid-year spike, says there is a question-mark over whether or not companies will be able to maintain profit growth. He estimates corporate earnings will rise 13 per cent this year and 15 per cent in 1994. He said: ''We are relatively relaxed about the economic outlook for Hong Kong, but higher interest rates would have an adverse impact on residential property companies' ability to grow rapidly. ''Bank margins are under some pressure, but investment property looks good with rentals performing well.'' A key feature of corporate earnings growth this year has been the vast profits creamed off property and securities holdings as the companies themselves join the rush to cash in on vibrant market conditions allowing them both to raise and spend cash on a big scale. Wheelock, formerly World International, earlier this week disclosed a 61.1 per cent rise in its interim profits, a jump largely attributable to treasury operations. Of the $214.4 million operating profit racked up in the six months to September 30, $86 million came from its investment activities. In keeping with this, HG Asia is backing Cheung Kong, in part for its extraordinary earnings on investments as well as the core property bookings. At Jardine Fleming Mr Ho, who is looking for earnings growth of 19 per cent in 1994, warns there may be a little too much caution in the market. He said: ''A couple of companies have come in ahead of expectations this year, especially Hutchison, which is going to be stronger than people think next year. ''With the banks I am a little more optimistic in general over how earnings growth will come through for this sector. ''Short term, I still believe that the infrastructure related theme will continue, and there are several large conglomerates for which their underlying quality of earnings is changing over time.'' A key example this year of a stock performing a volte face is Hopewell Holdings, which has more than doubled this year, largely on its move to spin off its power station projects for a separate listing. The company has long been attacked for its poor-quality earnings - each year impressive profits are achieved on the back of property sell-offs and other non-recurring income - but over time its direct stake in the power stations firm, Consolidated Electric Power Asia, should provide a more robust earnings platform. On top of this is the much-delayed super-highway across the border: again, once on line, returns should be handsome and certainly more substantial than those plucked off property sales. But the time-lag that is part and parcel of big-ticket infrastructure projects means that this change is unlikely to occur before 1998. Other companies to have put in a much better performance this year include Hutchison, after its investment in port terminals and the three winners, announced earlier this month, of contracts to provide a second fixed telephone network - Hutchison, Wharf and New World Development. ''I would argue that over the long term the quality of earnings in Hong Kong is improving, because we are shifting away from reliance on property development to more infrastructure projects,'' Mr Ho said. ''The contrary argument is that the completion risk on these projects is quite high, but they still hold a monopolistic position and clearly on completion if there are no big cost over-runs you are looking at very strong rates of return.'' Wardley James Capel head of research Philip Niem has a similar perspective. Mr Niem is expecting the commercial and industrial sector to provide some of the best performers next year. Overall, the British brokerage is looking for earnings growth of 16.6 per cent next year, with the property sector leading the pack on a 19.2 per cent rise and the commercial and the industrial sub-index close behind with a gain of 17.4 per cent. Barings is also looking to the hongs and property developers to put in some of next year's more shining performances while Lehman Brothers - which ranks at the forefront of the bulls with a year-end forecast of 12,000 in 1994 and corporate earnings growth of 18 per cent - reckons it will be a good year for telecommunications and media stocks. Head of research Kirk Sweeney is looking to TVB to lead the pack - even after this year's 147 per cent rise. ''To a certain extent the stock has been playing catch-up and I think it's a $40 stock,'' he said. It closed yesterday at $29.