Sovereign fund China Investment Corp is reviewing options for its 30 percent stake in French multinational electric utility Engie SA's exploration and production business, which it had bought for 2.3 billion euros in 2011.

According to people familiar with the matter, in July, the unit was seen having a potential to fetch about $4 billion.

The French utility, which operates in the fields of electricity generation and distribution, natural gas and renewable energy, is pushing ahead with a sale.