BEIJING - China's four major state-owned banks on Monday revealed the amount of A-shares that Central Huijin Investment Ltd.purchased in them in an effort to shore up confidence in the financial market.

In separate filings to the Shanghai Stock Exchange, the banks specified the purchases by Central Huijin on Thursday -- 42.93 million shares in Agricultural Bank of China (ABC), 24.49 million shares in China Construction Bank, 19.32 million shares in Industrial and Commercial Bank of China (ICBC) and 18.47 million shares in Bank of China.

After the purchases, Central Huijin now owns 40.24 percent of ABC, 57.23 percent of China Construction Bank, a 35.46-percent stake in ICBC and 67.74 percent of Bank of China, according to the filings.

The banks said Central Huijin will purchase more of their shares during the next six months.

China's key Shanghai index tumbled to a six-month low on Thursday, rocked by weak economic data and a sell-off in global markets.

Central Huijin, established in 2003,  is a state-owned investment company. It holds the Chinese government's stakes in commercial banks, securities companies, insurance firms and other institutions.