GUANGZHOU'S hotel industry has suffered as a result of the shortening of the Chinese Export Commodities Fair from 15 days to 10 days. Business brought about by the large spring and autumn trade fairs contributes the majority of annual revenue for joint-venture hotels, according to hotel industry experts. During the events, some hotels which cater for local and overseas businessmen increase their room charges by as much as 200 per cent. For example, the China Merchants Hotel, which is situated near the exhibition centre, increased its standard room charge from US$55 to $150. The hotel is a joint venture between Hongkong-based China Merchants Holding and the General Hospital of the Guangzhou Military Command. Capitalising on its proximity to the trade fair centre and the railway station, the 240-room hotel reported a profit of three million yuan (about HK$407 million at official rates) last year. ''No other hotel in Guangzhou can achieve such impressive results,'' said Mr Simon Kuang Guoquan, sales and marketing manager of the hotel. According to Mr Kuang, on normal days revenue from rooms is about 40,000 yuan, but when the trade fair is under way rooms can achieve a total revenue of more than 120,000 yuan. ''The reduction in the length of the trade fair has taken us by surprise because it means a great loss for us,'' said Mr Kuang. Another reform introduced at the current fair is the change from a general event to a special fair for light industry and textiles. ''This arrangement will narrow our customer base,'' said Mr Kuang.