PARIS, Jan. 14 (Xinhua) -- French Ecology Minister Segolene Royal on Thursday unveiled that Renault, France's second main car maker, did not use defeat software to cancel the level of gas emissions following first tests of the group's vehicles, a move likely to help calm morose investors.

　　"Tests don't prove the existence of defeat software of gas emissions at Renault," Royal said.

　　"The shareholders and employees can be reassured. Renault's cooperation is quite exemplary," she added.

　　However, tests on 22 first vehicles conducted by French Homologation Authority showed an excess in CO2 and Nitrogen Oxide emissions norms in Renault cars and in circulating units of foreign auto makers, according to the French minister.

　　As part of a government investigation on whether French manufacturers have cheating on level of pollutant emissions, the independent technical commission searched three sites of the auto company triggering a massive selloff of its stocks.

　　In a press release posted on its website, Renault said the probe found "no evidence of a defeat device equipping (its) vehicles."

　　"The on-going tests open the way for improvement solutions for future and current Renault vehicles. Presented in its Renault Emissions Plan which is aimed at improving the energy performance of our vehicles," the car manufacturer stressed.

　　On Thursday trading session, Renault limited its heavy losses of 23 percent reported in mid-trading session. At the closing bell, Renault stocks lost 10.28 percent to 77.75 euros (84,39 U.S. dollars) per share. (1 euro = 1.085 U.S. dollars)