Extreme volatility in global share markets could take a toll on BoC Hong Kong (Holdings)' listing debut on the main board today, but underwriters are expected to help stabilise the share price, analysts said. They expected the No 2 bank in the SAR by assets to see its share price dip below its initial offering price of HK$8.50, but few believed it would sink below the key psychological level of HK$8. Success of BoC Hong Kong's listing - the largest local share offering and the third-largest in the world so far this year - is a key milestone for China's banking sector. China's four giant state banks - plagued by huge non-performing loans due to years of state-directed lending - are undergoing reforms and eyeing overseas listings as a way to improve transparency and governance. BoC Hong Kong has some of the best assets of its parent, Bank of China, the mainland's largest foreign-exchange bank and second-largest bank. Its flotation will test international investors' appetite for a major mainland bank's key assets for the first time. Sentiment towards the banking sector was hurt badly following the more than 15 per cent share price plunge on Tuesday of the United States' two largest banks - Citigroup and JPMorgan Chase. The two banks are struggling with allegations by Congress investigators as to their roles in certain Enron-related transactions. The share price falls prompted investors to sell stocks in major international banks, with HSBC Holdings falling 3.3 per cent yesterday locally and a further 5 per cent to 700p at the opening in London trade. 'It will be very lucky if it doesn't fall below HK$8,' said Fulbright Securities general manager Francis Lun Sheung-nim, adding he believed a major support level for the stock would be HK$7.50. But other analysts said BoC Hong Kong was likely to end the trading day above the HK$8.075 level which retail investors paid for the stock - a 5 per cent discount on the institutional offer price. The HK$8.075 price is seen as an important level as 35 per cent of the shares offered were sold to retail investors who tend to have a shorter investment horizon and be more prone to panic-selling than institutional investors. Underwriters have the right to not exercise a 15 per cent over-allotment option and buy back shares from the market to offset the shares already allotted to institutional investors under over-allotment. The grey-market bid price was HK$8.15 last night, with an asking price of HK$8.50 compared with HK$8.70 two days earlier, according to iMarkets.com, which provides grey-market trading - the trading of shares ahead of their listing. The prices suggested little upside likely for BoC Hong Kong. But at least one analyst was relatively optimistic. Kitty Chan, associate director of Lippo Securities, said she believed the stock could trade at about its issue price for the first few days of trading. However, she noted the share price of international banks such as HSBC had been under pressure after the sharp fall in US banks, which were trading at price-to-earnings ratios of only about 10 times. At its share issue price, BoC Hong Kong commands a price to this year's forecast earnings ratio of about 14 times. 'Compared with the banks in Hong Kong, it seems to me BoC Hong Kong is not that attractive at the moment,' she said.