Central Huijin Investment Ltd, an arm of China's sovereign wealth fund, has increased its stake in China's four biggest commercial banks on Wednesday, sending the A-share market climbing on Thursday morning.

Central Huijin has bought shares in Bank of China, Agricultural Bank of China, China Construction Bank, and Industrial and Commercial Bank of China and plans to further boost holdings in the banks in the coming six months, according to disclosures of the banks on Wednesday.

About a total of 477 million yuan ($65.31 million) was bought by Central Huijin Investment Ltd on Wednesday, sending a positive signal that will strengthen investor sentiment, Hong Hao, chief economist at GROW Investment Group, said in a research note.

Specifically, the investment company bought 27.61 million shares in the Industrial and Commercial Bank of China and 37.27 million shares in the Agricultural Bank of China.

It also increased stakes in the Bank of China and the China Construction Bank by 24.89 million shares and 18.38 million shares, respectively, said their statements.

Xinhua contributed to this story.