---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-23-000787"
form_type: "8-K"
ticker: "AVA"
cik: "0000104918"
company_name: "AVISTA CORP"
filed_at: "2023-01-17T23:59:59+00:00"
generated_at: "2026-06-20T14:28:51.093296+00:00"
event_type: "m_and_a"
sentiment: "neutral"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Avista abandons 15% Colstrip Units 3&4 interest to NorthWestern with no cash consideration

## Summary
- Avista abandons 15% undivided interest in Colstrip Units 3&4 to NorthWestern; no purchase price is paid.
- Transaction scheduled to close December 31, 2025; Avista covers operating and capital costs until closing.
- Avista retains Colstrip transmission system assets and voting rights on remediation via a vote sharing agreement.
- Driven by Washington Clean Energy Transformation Act requiring coal-free electricity for retail customers after 2025.
- Other Colstrip owners have 90-day right of first refusal; deal subject to regulatory approvals and new coal supply agreement.

## SEC filing metadata
- accession: 0000950170-23-000787
- form_type: 8-K
- ticker: AVA
- cik: 0000104918
- company_name: AVISTA CORP
- filed_at: 2023-01-17T23:59:59+00:00
- event_type: m_and_a
- sentiment: neutral
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 1.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/104918/000095017023000787/0000950170-23-000787-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/104918/000095017023000787/ava-20230116.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-23-000787
- JSON: https://secwatch.observer/filing/0000950170-23-000787.json
- Plain text: https://secwatch.observer/filing/0000950170-23-000787.txt

## Key facts
- Material Agreements
  AVISTA CORP entered into a asset purchase with NorthWestern Corporation (effective 2023-01-16).
  - Action: entry
  - Agreement: asset purchase
  - Counterparty: NorthWestern Corporation
  - Effective: 2023-01-16
  source text: On January 16, 2023, Avista Corporation (Avista Corp. or the Company) entered into an agreement with NorthWestern Corporation (NorthWestern) under which the Company would abandon its 15 percent ownership in Colstrip Units 3 and 4, and NorthWestern would acquire ownership.
  evidence_url: https://www.sec.gov/Archives/edgar/data/104918/000095017023000787/0000950170-23-000787-index.htm

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.