PARIS — French auto maker Renault SA said Wednesday it plans to file a complaint Thursday before the criminal court in Paris in a case related to suspected industrial espionage, as two unions said they will press the company's management to say more on the spying scandal.

A Renault spokeswoman said she couldn't comment further on the company's legal action until after the complaint has been filed. The French public prosecutor's office wasn't immediately available to comment on whether it has taken up the Renault case, reported The Wall Street Journal.

Renault didn't specifically say against whom the complaint would be filed. But three employees have been suspended since Jan. 3 over suspicions they had leaked strategic information to third parties.

Separately, unions called for more light to be shed by the company. "The CFDT and the CFE/CGC will activate all levers internally to press Renault management to shed light on this affair in terms of the consequences that could prejudice the interests of the company and all its personnel," the unions said in their joint statement. A Renault spokesman declined to comment on the union statement.

One of the three executives suspended in the affair told reporters Tuesday that he hadn't engaged in espionage. "Renault is making very serious accusations against me that I totally refute," Michel Balthazard, a member of Renault's management committee said. "The facts were outlined to me, and I refute them as well."

Renault last week suspended the three employees suspected of providing proprietary information about the company's multi-billion dollar joint electric-car program with Japanese affiliate Nissan Motor Co. Ltd. to outside interests it hasn't identified. News reports have linked Chinese interests to the affair, irking the Chinese government, which has denied involvement. The company has said it suspected an organized spying effort.

French Finance Minister Christine Lagarde said Wednesday there was no assumption of involvement by another country or an organized spy ring. She cautioned French companies, however, to realize that industrial spying takes place and that they must take precautions.

The French secret service has been reported to have been mobilized to investigate the case, while the government is considering measures to toughen its laws against industrial espionage.