A Houston-based subsidiary of France’s Total SA and two of the company’s West Desk traders and supervisors allegedly developed a scheme to manipulate the price of natural gas in the southwest United States between June 2009 and June 2012, according to staff in FERC’s Office of Enforcement.

Total Gas & Power, North America Inc.’s (TGPNA) Therese Nguyen and Aaron Hall violated section 4A of the Natural Gas Act and the Federal Energy Regulatory Commission’s Anti-Manipulation Rule by devising and executing a scheme to manipulate gas prices over the three-year period, FERC staff said in a Notice of Alleged Violations issued Monday.

“Staff alleges that the scheme involved making largely uneconomic trades for physical natural gas during bidweek designed to move indexed market prices in a way that benefited the company’s related positions,” FERC staff said. “Staff also alleges that the West Desk implemented the bidweek scheme on at least 38 occasions during the period of interest.”

Nguyen and Hall each implemented the scheme and supervised and directed other traders in implementing it, according to FERC.

Calls to FERC and the Total office in Houston were not returned as of time of press.