(Yicai) April 15 -- Central Huijin Investment, a sovereign wealth fund set up by China's central bank, has raised its stake in the country's big four state-owned banks by nearly 1.1 billion shares over the past six months.

Central Huijin bought 401 million shares of Agricultural Bank of China from October through April 10, 71.5 million of China Construction Bank, 330 million of Bank of China, and 287 million of Industrial and Commercial Bank of China, according to data released by the four lenders on April 12.

The newly purchased stock represents around 0.1 percent of the total shares of each of ABC, BOC, and ICBC, and 0.03 of CCB.

Last October, Central Huijin bought shares of the big four banks for the first time in eight years and said it planned to go on buying their stock in the secondary market over the following six months.

Beijing-based Central Huijin, an arm of China Investment Corporation, invests in key state-owned financial firms, but is not involved in their daily operations.

Shares of the four banks have surged since Central Huijin began its latest purchases, with BOC [SHA: 601988] climbing 19 percent as of April 12, ABC [SHA: 601288] 18.6 percent, ICBC [SHA: 601398] 13.7 percent, and CCB [SHA: 601939] 12.3 percent.

Central Huijin raised its holdings in the four lenders in 2008, 2009, 2011, 2012, 2013, and 2015, which was met with positive feedback in the secondary market.

Editor: Martin Kadiev