Investors will scour a preliminary prospectus for Agricultural Bank of China's around $30 billion IPO, the world's largest, for updates on its book value and bad loans.

AgBank's IPO draft documents are expected later on Friday as part of China's fourth-biggest bank's dual listing in Shanghai and Hong Kong, slated for mid-July.

The last official financial data from AgBank were its 2008 results, though the Wall Street Journal reported on Friday that the bank's 2009 core capital adequacy ratio was 7.74 percent, just below the government's required 8 percent. The paper said it obtained the information ahead of the data's release.

Awaiting the financial disclosure ahead of such a big initial public offering, one Hong Kong-based fund manager said there were concerns over AgBank's exposure to local government funding platforms and its high cost-to-income ratio, given the bank's many branches and staff numbers.

But the fund manager, who could not be named as he was not authorized to speak on the record to the media, said AgBank should offer high growth given its rural population focus, low non-performing loan levels and low leverage.

Dutch Rabobank said it signed a strategic cooperation with AgBank to share its experience in wholesale banking, rural finance and other operations.

Rabobank, cooperatively owned with its roots in and focus on the farming community, did not say whether it would become an investor in AgBank prior to the IPO.

AgBank is the last of China's big four banks to list its shares and the first to do so without first bringing in a major foreign strategic investor, underscoring how the global financial crisis has dented the reputation of foreign banks in China.

The China Daily reported in March that AgBank's 2009 net profit rose 26.3 percent to 65 billion yuan ($9.52 billion) on operational reforms and a broader lending binge by Chinese banks under Beijing's loose monetary policy.

Sources with direct knowledge of the matter told Reuters on Thursday that the China Securities Regulatory Commission (CSRC) would release AgBank's preliminary IPO prospectus late on Friday, giving investors a first glimpse of key financial information on the company since the 2008 year-end report.

AgBank plans to seek approval on June 10 from committees that oversee listings in Shanghai and Hong Kong, sources say. The bank would then begin premarketing its IPO, aiming to debut its A-shares in Shanghai on July 15 and its Hong Kong H-shares a day later, the sources said.

The planned Friday prospectus release is for the Shanghai A-share offering, although it may also include information related to the Hong Kong part of the IPO.

Investors will be looking for key gauges such as book value to decide whether AgBank, size and all, is worth putting money into. Beijing-based AgBank's big domestic rivals trade at near or above 1.6 times book value.

According to a BofA Merrill Lynch report, Industrial and Commercial Bank of China (ICBC) <1398.HK> trades at 2.1 times 2010 price-to-book, P/B, Bank of China <3988.HK><601988.SS> at 1.5 times, and Bank of Communications <601328.SS> at 1.8 times.

Exposure to non-performing loans is another key measure investors will watch keenly. ($1=6.828 Yuan) (Additional reporting by Daisy Ku in HONG KONG; Gilbert Kreijger in AMSTERDAM; Editing by Chris Lewis and Ian Geoghegan)