Bidders showing interest in Attero stake

China Gezhouba Group Corp, builder of the world's biggest hydroelectric dam, and Beijing Enterprises Holdings Ltd, are among groups that made first-round bids for Dutch waste management company Attero, company sources said on Thursday.

State-owned China Energy Conservation & Environmental Protection Group also submitted an indicative offer by the end-September deadline, the sources said.

The sale, which has also drawn interest from Beijing Capital Group Co, could value Attero at about $800 million to $1 billion, the sources added.