As expected, the IPO will take place simultaneously on the Hong Kong and Shanghai exchanges. There is still uncertainty about the number of shares to be offered, with estimates for the Shanghai 'A'-share tranche varying between 13 billion and 17 billion, and the Hong Kong 'H'-share tranche more or less firmly set at 40 billion shares, assuming that there is adequate over-subscription.

Even at the lower end of estimates, the IPOs will raise a world-record US$19bn, and the tally might go as high as US$21bn, representing around 16.5% of the bank's share capital. The previous record was set by Japan's NTT in 1998, which raised US$18.4bn.

There are worries about the llevel of investor interest, however. Last month, Air China had to reduce its Shanghai IPO by nearly 40%. Hong Kong IPOs this year have been strong, and previous Chinese banking IPOs have been successful.

China has been re-capitalizing and floating its banks ahead of the sector's forced liberalization next year under the terms of its WTO entry. Altogether, more than US$60bn has been injected into the top four banks in order to deal with non-performing loans and Tier 1 capital weaknesses.

Merrill Lynch is lead underwriter for the ICBC float; other book-runners include Credit Suisse Group, Deutsche Bank, China International Capital, ICEA Finance Holdings, Shenyin & Wanguo Securities, and CITIC Securities.

ICBC is receiving special tax exemptions in order to attract investors. According to a notice published by China's State Administration of Taxation ICBC will re-evaluate all of its assets prior to the listing, but will not be liable for corporate tax on profits earned from assets that have grown in value since their purchase. In addition, any depreciation charges following the re-evaluation of the assets will also be exempt from taxes.