Industrial & Commercial Bank of China (ICBC) has deposed US-based Wells Fargo & Co to become the world's most valuable bank.

Since overtaking the 163-year-old Wells Fargo on 7 April, Beijing-based ICBC has extended its lead.

ICBC's market capitalisation stood at some $317bn (£209bn, €293bn) at close on 24 April in Hong Kong, while NYSE-traded Wells Fargo was worth $282bn.

Meawnhile, Chinese banks remain the cheapest the worldover, trading at about 7.8 times estimated earnings for 2015, the lowest for lenders with a market value of over $10bn, according to Bloomberg data.

ICBC, founded in 1984, trades at 1.1 times estimated book value, compared with 1.6 times for Wells Fargo.

Steven Chan, analyst at Maybank Kim Eng Securities in Hong Kong believes that Chinese lenders' were drawing support from monetary easing lowering their funding costs and limiting bad loans. Beijing has cut interest rates and lenders' reserve requirements twice since November 2014.

Chan told Bloomberg: "The next round of the rally is likely to be related to some of the foreign institutional investors realising that they've been too pessimistic about China's banks."

The stock boom in China means that the country's large state banks now make up four of the world's top six lenders by market value.

ICBC's shares have also been boosted by new Chinese investors buying shares with borrowed money.

Brokerages had extended more than CN¥ 120bn ($19.4bn) for purchases of banking shares as of 20 April, including CN¥ 7.5bn for ICBC stock, according to data from the Shanghai and Shenzhen bourses.