China's aviation regulator will permit mainland airlines to double their surcharges to ease fuel cost pressure on the cash-strapped carriers but few airlines expect the charges will raise their bottom lines. According to China Eastern Airlines, quoted in a mainland newspaper, the General Administration of Civil Aviation of China (CAAC) had allowed the three big airlines - China Southern Airlines, China Eastern Airlines and Air China - to raise fuel surcharge per passenger between 104 per cent and 114 per cent. From the mainland to the Asia Pacific region (excluding Japan), fuel surcharges per passenger will increase from 98 yuan to 210 yuan. It is the second time this year that mainland airlines have adjusted their fuel surcharges on international routes. 'While we have not received a formal letter yet, it is common practice to be able to adjust the fuel surcharge to keep parity with international carriers on the same route,' said Rao Xin-Yu, investor relations manager at Air China. Air China, which draws 40 per cent of its passenger revenue from international traffic, is likely to benefit most from the surcharge increase. However, analysts and other carriers believed any gain would be offset by the normal drop to low season ticket prices. 'The fourth quarter is traditionally the low season. I wonder how much the carriers will have to trim their ticket price due to the weakness in demand,' said Ella Li, analyst at Shenyin Wanguo Sercurities. 'Surcharges in both the passenger and international cargo segments are expected to boost the revenue [of China Eastern] by around 940 million yuan next year. However, we expect this to be offset by higher fuel and interest costs,' Paul Dewberry, an analyst at Merrill Lynch, said in a report. The share prices of China Eastern Airlines and China Southern Airlines plunged yesterday - China Eastern dropping 4.7 per cent to $1.02 and China Southern plunging 3.6 per cent to $2.00. Air China closed unchanged at $2.425. Fuel costs, which comprise one-third of the airlines' total costs, have hurt China Southern Airlines and China Eastern Airlines this year with both slipping into the red.