HONGKONG'S rumour mill was in top gear again yesterday following market reports that the Lai Sun Group would buy the Ritz-Carlton for $1.3 billion. There was also speculation that the hotel's management contract had been reduced to 10 years from 25 years. For a while it appeared that the long-running saga of the Ritz-Carlton had finally come to an end. It appeared that someone had agreed to put up enough cash to allow the hotel's doors to open and allow in its first guest. With the Easter long weekend almost here, those available for comment were few and far between. The firm of accountants running the hotel, Deloitte Touche Tohmatsu, was tight-lipped about the rumours and receiver Joseph Lo's reply to all questions was a curt ''no comment''. Further confusion arose when some of those peddling the rumours were unable to say whether the company said to be due to buy the Ritz-Carlton was Lai Sun or Hysan. There was also even some mention of interest being shown by a mainland party. However, once the initial dust had settled what became patently clear was that the property had not found a buyer yet. Negotiations for the property involving a number of parties - including Hysan Development, Lai Sun and Furama Hotel Enterprises - are still continuing. The hotel was built by the former owner, GGS Hotel Holdings of Japan, which was subsequently unable to repay loans it borrowed to do so. In August 1991 some of the banks involved in the loan syndication quit to cut their losses, leaving the stricken hotel in the hands of the receivers, where it has been ever since. Lai Sun Group's name has come up as a potential buyer before, but in December 1992 director Billy Hung was reported as saying that his company had abandoned plans to buy as no agreement on the price tag could be reached. One of the major stumbling blocks in the negotiations has been and probably continues to be the hotel's management contract, which has been described as ''very tight planned''. Not that the price tag for the 25-storey, 216-room building is exactly a snip at $1.3 billion. This asking price is probably going to set back any potential purchaser for a number of years still; it is equivalent to the hotel selling its rooms at an average room rate of $5,000 a night. It may well be some years before room rates in the territory match this, despite Hongkong's high rates of price and wage inflation. Some property agencies have described this average room rate as phenomenal. It is simple to see that the hotel could never be a profitable concern at $5,000 per room. Most property agents agree that if the $1.3 billion price is to be paid, the new owner will need to consider either redeveloping the building or the site. As Mr Chris Thrift, director of Richard Ellis, said in February: ''The best way of dealing with the Ritz-Carlton is to rip the whole building down and start again''.