CENTRAL Huijin Investment Ltd, a unit of China's sovereign wealth fund, increased its stake in the nation's four biggest banks last week.

The investment arm of the China Investment Corp purchased 19.3 million yuan-denominated A shares in the Industrial and Commercial Bank of China, 24.5 million in China Construction Bank, 18.5 million in the Bank of China and 42.9 million in the Agricultural Bank of China on Thursday, the four lenders announced in separate exchange statements yesterday.

Central Huijin will continue to purchase shares in the banks in the following six months, according to the statements.

The Shanghai Composite Index has declined 11 percent from this year's high set on February 6 amid concern the economic recovery will falter.

The mainland-traded shares of AgBank have decreased 4.6 percent this year while those of the other three biggest lenders are virtually unchanged.