DALLAS — Marcus Cable Co. L.P. posted a first-quarter loss of $32.9 million on revenues of $126.9 million.

In a press release Monday, the operator of domestic wired telecommunications networks said its earnings before interest, taxes, depreciation and amortization were $58.8 million for the quarter ended March 31.

On a pro-forma basis, to normalize the effects of acquisitions, divestitures and other adjustments, Marcus’ first-quarter revenues and EBITDA increased 10.9% and 11%, respectively, from a year earlier.

The company said its basic customers and premium units for its owned systems were 1.2 million and 559,475, respectively, at March 31. Basic customers increased by 3,865 from Dec. 31, 1997.