The Agricultural Bank of China is seeking to raise over $23 billion by listing in Hong Kong and Shanghai in what would be the world's biggest IPO, as China's banks shore up their capital base after a lending spree.

In addition to new financial information about the issue on Monday, Asia's third and fourth richest individuals have signed up as cornerstone investors, a report said.

Cheung Kong (Holdings) chairman Li Ka-shing and chairman of Henderson Land Lee Shau Kee will each subscribe to HK$1 billion ($128.3 million) of AgBank shares, Infocast News reported on Monday.   

Li, Asia's third wealthiest person who Forbes says is worth $21 billion, and Lee routinely subscribe to large, Hong Kong IPOs.

The initial public offering by AgBank, founded by Mao Zedong in the 1950s as the central bank's rural arm, had previously been touted as high as $30 billion, but has been scaled back as China's stock market has dropped by more than a fifth this year and global markets have been spooked by a euro zone debt crisis.

AgBank's offering comes as China's second-largest wind turbine maker, Xinjiang Goldwind Science & Technology Co, pulled a $1.2 billion IPO, the fifth Hong Kong offering to be shelved since last month, citing weak markets. - Reuters