PITTSBURGH — A utility company has sued a Dallas waste management company, claiming it reneged on a deal to repay more than $875,000 in overcharges.

Dallas-based Oncor Electric Delivery Co. LLC reached an agreement with GLM DFW Inc. after a third-party audit allegedly revealed that GLM overcharged by 2 cents per pound, according to documents filed in U.S. District Court in Texas.

The scrap arm of Commercial Metals Co. (CMC)—which is accused of no wrongdoing—processed the material for GLM. When Oncor compared bills issued by GLM with CMC’s bills between 2006 and 2010, a markup of $876,036 was allegedly discovered, according to the court documents.

In the original agreement between the two companies, GLM would deduct its fee to process Oncor’s scrap metal and the two entities would split the net profits. Once Oncor auditors discovered the overcharge, GLM president Mary Galvan agreed to repay the amount in two installments in March and June 2011, according to the lawsuit.

Oncor delivers power to 3 million homes in Texas, and its 117,000 miles of transmission lines generate substantial amounts of scrap metal, the court documents state.

Oncor said it received one installment for about half of what it is owed. It is suing to receive the balance, as well as court costs, according to the lawsuit.

Galvan couldn’t be reached for comment.