By Jaime Llinares Taboada

U.K. energy watchdog Ofgem said Wednesday that Electricite de France S.A. sent misleading signals to National Grid ESO for more than two years by inflating the minimum amount of power that its West Burton B power plant could supply.

As a result of EDF's actions between Sept. 2017 and March 2020, British electricity-system operator National Grid had to buy more energy from the gas-fired plant than needed when the site's generation was used to balance the system.

The French electric utility company inadvertently breached obligations that prohibit market manipulation, the regulator found. EDF has admitted to the breaches and has agreed to make a voluntary payment of 6 million pounds ($8.1 million).

EDF didn't consider its approach would result in increased costs for the system, but that it would allow it to provide lower prices by recovering fixed costs over a greater volume, Ofgem said. EDF acknowledged that its strategy sometimes resulted in the system operator spending unnecessary money to balance the power system, the regulator said.

"We have taken swift action to prevent any reoccurrence. We have changed our approach and ensured it is fully aligned with the clarification in Ofgem's latest guidance and put in place new governance arrangements to ensure ongoing compliance," EDF said.

Write to Jaime Llinares Taboada at jaime.llinares@wsj.com; @JaimeLlinaresT

(END) Dow Jones Newswires

12-16-20 0501ET