Regulator fines National Grid $81 million

London -- British energy regulator Ofgem fined London-based National Grid a record $81 million Monday for placing restrictive language on contracts.

Ofgem charged that energy giant National Grid's contracts with other energy companies included wording that penalized them for replacing broken National Grid gas meters with other brands, a practice that unfairly monopolized the gas meter industry.

"Ofgem has imposed a substantial fine on National Grid for a serious breach of competition law," Ofgem Chairman John Mogg said.

"The abuse has prevented suppliers from contracting with other companies for cheaper metering deals and could discourage suppliers from installing smart meters," he said.

National Grid said the practice encouraged repairs and saved its customers $236 million over four years.