PARIS, July 22 (Reuters) - Europe's largest listed car part maker Valeo posted lower second-quarter net profit on Thursday due to smaller one-off gains, but bolstered operating profit thanks to a nascent revival in the European auto market. The maker of clutches, windscreen wipers and parking gadgets said net profit totalled 46 million euros compared to 80 million a year ago, when it pocketed a one-off tax rebate. Operating profit was 140 million euros in the quarter.