HELENA (AP) - NorthWestern Energy filed suit Monday against the state Public Service Commission over the panel's decision to cut NorthWestern's request for a natural gas rate increase.

In a written statement, the company said the PSC's ruling prevents NorthWestern from recovering more than $6 million in actual natural gas costs it incurred over the winter, and that its decision ''ignored the advice of the PSC staff and the Montana Consumer Counsel.''

The company's lawsuit, filed in District Court in Helena, claims the company could potentially lose another $6 million because of the decision...