Chinese shares tumbled at the opening Wednesday after the country's central bank announced late Tuesday it would raise the deposit reserve requirement ratio.

The benchmark Shanghai Composite Index dip 2.11 percent at 3,204.98 points.

The Shenzhen Component Index lost 2.61 percent to open at 13,031.55 points.

This is the first time that the PBOC adjusted the ratio of deposit that lenders are required to set aside since the end of 2008 and the first increase for the ratio since June of 2008.

The PBOC has cut the bank reserve requirement ratio for four times in the second half of 2008 to stimulate growth as the global financial crisis started to weigh on the economy.