JACKSON, Miss. (AP) — Federal officials say Entergy Corp. can buy two power plants from KGen Power Corp., but say the antitrust investigation of Entergy isn't over.

The New Orleans utility wants to buy generating stations in Jackson, Miss., and Malvern, Ark., from Houston-based KGen for $523 million. Purchases of the natural-gas fired plants were frozen by the investigation into whether Entergy used control of transmission lines to harm independent power generators like KGen.

The Justice Department said Wednesday that Entergy can complete the purchase, and Entergy expects to do so by year's end. Officials say Entergy's plans to join a regional transmission organization called MISO and spin off long-distance power lines to ITC Holdings Corp. will end antitrust concerns. However, Justice officials say if Entergy doesn't take those steps, it may still act.