China Rongsheng Heavy Industries Group, the country's largest private shipbuilder, said on Monday its chairman had stepped down to devote more time to his personal endeavors.

The company said in a statement on the Hong Kong stock exchange that Zhang Zhi Rong would be replaced by Chief Executive Officer Chen Qiang, effective immediately.

It added that Zhang De Huang had resigned as an executive director of the company and as vice-chairman of the board for retirement reasons.