American Electric Power Co.'s (AEP) Texas utility filed a request Friday with state regulators to raise rates by about 20%.

AEP Southwestern Electric Power Co., or Swepco, is asking the Texas' public utility commission for an additional $75 million through rates for infrastructure, ongoing operations, increased vegetation management and ongoing financing costs related to power plant construction. If approved, the hike would be the utility's first increase in base rates in more than 25 years.

The increase would raise rates for customers in Swepco's east Texas service area by about 21.5%, or $16 a month for a typical household. The increase would only be 7% for customers in north Texas, since they're already paying higher rates, the utility said.

Swepco is asking for the new rates to take effect next spring, resulting in the same rates in both service areas.

"For many years, we have been able to absorb or offset these kinds of non-fuel cost increases, but we have reached a point where a rate increase is necessary," said Paul Chodak, Swepco's president and chief operating officer.

The higher rates will allow Swepco to recover financing costs for two power plant projects, the John W. Turk Jr. plant in Arkansas and the J. Lamar Stall unit in Louisiana.

-By Mark Peters, Dow Jones Newswires; 212-416-2457; mark.peters@dowjones.com