Agricultural Bank of China's Shanghai initial public offering drew Rmb30 billion (around $4.43 billion) in bids from potential strategic investors on its first day of bookbuilding, showing high demand for what may prove to be the largest-ever IPO, media reports said.

AgBank is raising more than $20 billion via a dual-listing in Shanghai and Hong Kong. The strong interest in Shanghai follows a similar showing in Hong Kong, where AgBank's offering was more than 10 times oversubscribed by institutional investors.

The bank is the last of China’s big four banks to float on the public market.

The IPOs of such banks will put them under more pressure to deliver results that can pass muster with sometimes jaundiced investors and also requires these institutions to divulge more information about their business lines, including wealth management.

AgBank plans to sell up to 10.23 billion shares in its Shanghai offering at Rmb2.52-2.68 to strategic investors.