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Jan 3 (Reuters) - The Idaho Public Utilities Commission has rejected Canadian electric utility Hydro One Ltd's proposed C$6.7 billion ($4.97 billion) acquisition of Avista Corp, the companies said on Thursday.
The companies said they are reviewing the order.
The regulator's decision follows last month's rejection of the proposed deal by a Washington state regulator saying it would not adequately protect Avista or its customers from political and financial risk.
In 2017, Hydro One had proposed to buy its U.S. peer Avista as it sought to expand into the U.S. Northwest. ($1 = 1.3493 Canadian dollars) (Reporting by Arundhati Sarkar in Bengaluru; Editing by Shailesh Kuber)