PPL Corp. of Allentown said today it would seek regulatory approval to build and operate a nuclear generating unit near the existing Susquehanna nuclear plant in Columbia County, Pa.

The energy company said that while it has not decided to proceed with construction, it would file a Nuclear Regulatory Commission license application for the unit, in Berwick, in 2008. This time frame will help preserve the potential for federal production tax credits and federal loan guarantees, PPL said.

It has contracted with an affiliate of UniStar Nuclear Energy to prepare the application.

PPL said a decision to build the plant would depend on such factors as finding a partner to share the cost. It is in talks on a possible joint venture, the company said.

The project is being developed by a PPL subsidiary, PPL Nuclear Development L.L.C. The Susquehanna plant now has two units.

PPL shares were down 4 cents this morning at $53.39 on the New York Stock Exchange.