TORONTO and SPOKANE, WA, May 25, 2018 /PRNewswire/ – Hydro One Limited ("Hydro One") (TSX: H) and Avista Corporation ("Avista") (NYSE: AVA) today announced the achievement of an important milestone in the regulatory approval process of their proposed merger. The companies have filed an all-parties, all-issues settlement agreement in the merger proceeding before the Public Utility Commission of Oregon ("OPUC"). This represents a full settlement which all parties have agreed is consistent with the public interest and will provide net benefits to Avista's Oregon customers. The settlement agreement is subject to review and approval by the OPUC.