Avista Plunges as Regulators Reject $3.4 Billion Hydro One Deal

Avista Corp. plunged the most in 16 years after Washington state regulators rejected the U.S. utility’s $3.4 billion acquisition by Canada-based Hydro One Ltd., dealing a potentially fatal blow to the deal.

Avista fell 14 percent to $43.95 at 9:48 a.m., Dec. 6, in New York, after sliding as much as 15 percent, the most intraday since June 2002.

The proposed deal doesn’t adequately protect Spokane, Wash.-based Avista or its customers from political and financial risks and doesn’t provide a net benefit to customers, according to a statement Dec. 5 from the Washington Utilities and Transportation Commission. The sale needs ...