Montana Public Service Commission(PSC) has given the go ahead for PPL Montana to sell its hydroelectric assets in the US state to NorthWestern Energy in a $900 million deal.

The PSC yesterday voted to prepare an order approving NorthWestern Energy’s request to purchase the facilities, which includes PPL Montana’s 11 hydroelectric power plants with a combined generating capacity of more than 630MW, as well as the company’s Hebgen Lake reservoir.

"The decision keeps us on track to close the transaction promptly and to deliver attractive value to PPL shareowners," said William H. Spence, chairman, president and Chief Executive Officer of PPL Corporation (NYSE: PPL), which owns PPL Montana.

Prior to the PSC’s decision, PPL Montana and NorthWestern had secured required approvals from the Federal Energy Regulatory Commission, as well as the necessary clearance from the antitrust enforcement agencies. In its actions, FERC approved the transfer of PPL Montana’s hydroelectric generating stations and its hydroelectric operating licenses to NorthWestern upon close of the transaction.

Before the transaction can close, NorthWestern must file with FERC and obtain routine approval of certain financing transactions. FERC review of that filing is expected to take 30-60 days.

The agreement does not include PPL Montana’s interest in the Colstrip facility or its J.E. Corette coal-fired facility located near Billings. PPL Montana has announced that it intends to mothball the 153MW Corette plant in April 2015. It also does not include the Butte-based marketing and trading operations of PPL Montana’s affiliate, PPL EnergyPlus, LLC.

PPL Montana’s hydroelectric facilities include its Thompson Falls Dam on the Clark Fork River; Kerr Dam on the Flathead River; Madison Dam on the Madison River; Mystic Lake Dam on West Rosebud Creek; and Hauser, Holter, Black Eagle, Rainbow, Cochrane, Ryan and Morony dams along the Missouri River.