(Bloomberg) -- Former Glencore Plc trader Emilio Heredia pleaded guilty to manipulating an oil price benchmark, allowing companies he worked for to profit from the price swings.Heredia appeared by video conference on Wednesday in federal court in San Francisco and, with his plea, admitted to a charge of conspiracy. He directed buy and sell orders that pushed fuel oil prices up and down so he and his co-conspirators could illegally enrich themselves, according to the U.S.

Prosecutors didn’t name the companies that profited from the scheme. Glencore, the world’s largest commodities trader, has said it is cooperating with authorities.

Read More: Former Glencore Trader Charged With Oil Price Manipulation

The investigation that led to Heredia’s plea is the latest legal setback for Glencore, already embroiled in a wide-ranging probe by the U.S. Department of Justice on allegations of bribery and money laundering. The U.K., Switzerland and Brazil are also investigating the company. Authorities around the world are increasingly policing commodities trading and the companies that dominate it, while making a renewed push against market manipulation.

Illegal Gains

According to prosecutors, Heredia directed his co-conspirators to submit bids and offers through S&P Global Platts, a benchmark price publisher, in an effort to artificially change price assessments so his firm could buy fuel oil from another company at a lower price or sell it at a higher price. In one example, in 2016, Heredia directed a co-conspirator to lower the benchmark price 41 times, resulting in hundreds of thousands of dollars in illegal gains for his company, the government said.

Read the charging document here

“We note charges of attempted manipulation of certain S&P Global Platts assessments but do not believe that any such attempts were successful and no court has ruled to the contrary,” the company has said.

The case is U.S. v. Heredia, 21-cr-00109, U.S. District Court, Northern District of California (San Francisco).

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