A security guard patrols outside Wison Engineering Services Co Ltd, in Shanghai September 3, 2013. China oil construction company Wison Engineering Services Co Ltd said its chairman and controlling ... more 
A security guard patrols outside Wison Engineering Services Co Ltd, in Shanghai September 3, 2013. China oil construction company Wison Engineering Services Co Ltd said its chairman and controlling shareholder Hua Bangsong "is assisting relevant authorities" in China who are conducting an investigation after sharp falls in Wison's share price. Wison, which counts PetroChina among its major customers, did not elaborate on the investigation. It said it issued the statement after Chinese media reports about its business relationship with PetroChina. REUTERS/Aly Song (CHINA - Tags: BUSINESS COMMODITIES ENERGY) less 
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Reuters | Photo By ALY SONG / REUTERS
Tue, Sep 3, 2013 2:00 AM EDT