THE share price of Cathay Pacific Airways fell further yesterday, closing 15 cents down at $9.25 as the mounting costs of the airline's continuing strike became clearer. Updated analysts' estimates have put the cost of the flight attendants' strike at up to $25 million a day and rising. The daily loss of profits could rise considerably during the Lunar New Year if industrial action continues over the peak holiday period. This is likely if the Flight Attendants' Union rejects Cathay's offer of a seven-day truce from tomorrow. The extra number of passengers booked to travel during the holiday period would probably mean additional expenses incurred because more aircraft would be needed to be chartered from other carriers to transport passengers stranded at Kai Tak. The strike has come at the worst time of the year for Cathay. Flights during the Lunar New Year holiday, which this year begins on Friday, are normally fully booked, yields for the airline are higher and additional flights are scheduled. Analysts have increased their estimates of Cathay's daily losses from $10 million on the first full day of the strike, partly due to the rising number of services being operated on Cathay's behalf by rival airlines. On the first day of the strike, five services were operated by other carriers. The number rose to nine on the second day and 18 yesterday, and 22 are expected today. Mr Philip Mok Wan-yu, head of research at Barclays de Zoete Wedd, said while the strike had a significant impact on Cathay's earnings in the short run, the long-term consequences of the dispute were more serious, especially if it was allowed to continue for a prolonged period. ''They are losing market share,'' he said. ''That's something that takes quite some time to rebuild.'' Mr Mok said the dispute had caused short-term selling pressure on the shares of both Cathay and its parent, Swire Pacific. However, the impact on Cathay's share price is not expected to be too dramatic as the stock has consistently underperformed the recovering stock market since early last month, with most brokers advising clients to sell. Yesterday, the stock closed 15 cents down, adding to the 20-cent loss last Friday. Swire Pacific A fell another 50 cents to $31 yesterday, after shedding 50 cents last Friday. ''The dip is not that substantial,'' said Seapower Securities research manager Samuel Lau. ''I think the share price has already discounted part of the bad news.'' Cathay has been tight-lipped over the costs incurred, saying its priority now was to shift passengers rather than calculate losses. However, Mr Sheldon Kasowitz, a senior analyst and director at Jardine Fleming Asia Research, reckoned Cathay could see a five to 10 per cent drop in estimated earnings of $3.7 billion for this year if the strike continued through the Lunar New Year holiday. SBCI estimated daily revenue loss at 50 per cent and daily costs to have risen to up to $25 million. Mr Tony Swift, SBCI analyst, said: ''Cathay does not have much chance to increase profits over the next couple of years and because of this it has been seen as a pretty boring share.'' While Cathay has continued to remain profitable, it has felt forced to embark on a major cost-cutting programme to remain so. It has been these cut-backs that have partly resulted in the strike. Higher than average operational costs mean Cathay will lose 14 per cent productivity compared with its competitors by 1997, unless changes are made. Cathay's management consultancy firm, Cresap, recently reported that if the airline's revenue was to increase at the world inflation rate and costs rose at a mix of the Hongkong and world inflation rates, it would be at break-even point by 1997 and losing substantial amounts by 2002. Last year, Cathay said it would shift some of its data-processing operations to Guangzhou to take advantage of lower labour costs in the mainland city. It is also transferring its computer centre to Sydney, Australia, to capitalise on lower property prices. The management's cost-cutting efforts have impressed analysts at Lehman Brothers. Their latest report said: ''Although the airline industry is highly competitive and although we maintain long-term concerns about the industry in the region, we believe that through tight control of costs, stronger yield management and an expected recovery in the United States economy, yields will remain stable and unit costs should fall slightly. ''We forecast a 27 per cent rise in Cathay's first-half earnings per share.''