China's state-run Central Huijin Investment Co has increased its stake in the Industrial and Commercial Bank of China and the Bank of China this year to bolster support for the lenders, the banks' statements showed on Friday.

Central Huijin boosted its holdings in ICBC, the world's biggest bank by market value, by 50.3 million shares, and added 83.6 million shares in BOC in the first quarter of this year, based on calculations on Friday's statements to the Shanghai Stock Exchange and earlier filings.

The banks' stock prices have rallied more than 4 percent in Shanghai since Central Huijin bought shares on October 10 to support the market and pledged to continue buying.

ICBC statement also showed that China Ping An Life Insurance Co bought a massive 320 million shares in the first quarter.

Buying actions of Central Huijin, which was set up to hold the government's stake in the nation's biggest lenders, are usually taken by analysts as an indicator for stronger performance of the stock market.

Chinese banks' valuations last year fell below the level reached during the 2008-2009 global financial crisis on concern that loans may sour as the economy slowed and the government maintained curbs on the property market even though they reported record profits for 2011. Earnings reports of 12 listed banks showed their combined profits reached 849 billion yuan (US$135 billion), nearly 30 percent higher than a year earlier.