NorthWestern Energy agrees to all-stock merger with Black Hills at 0.98 exchange ratio
On August 18, 2025, NorthWestern Energy entered a merger agreement with Black Hills Corp. under which each NorthWestern share would convert into 0.98 Black Hills shares. The companies say the exchange ratio implies an approximately 4% premium based on volume weighted average prices since March 2025, and the combined company would have a $15.4 billion enterprise value. Completion requires shareholder and regulatory approvals and is expected in 12 to 15 months, so NorthWestern shareholders face approval and closing risk before the terms take effect.
Key points
- Each NorthWestern common share converts into 0.98 Black Hills shares; Black Hills holders would own about 56% and NorthWestern holders about 44% of the combined company.
- The exchange ratio implies an approximately 4% premium based on volume weighted average prices since March 2025, per the companies' press release.
- Either party owes a $100 million termination fee in certain circumstances; the agreement can be terminated if closing has not occurred by August 18, 2026, extendable up to February 18, 2027.
- Brian B. Bird, NorthWestern's CEO, is expected to become CEO of the combined company; Linn Evans, Black Hills' CEO, will retire at closing.
The filing
Written by AI on Nov 8, 2026, 1:05 AM ET, from this filing only. Written later: this filing was briefed after the fact, when past filings were added to the site, so the brief may be read with hindsight; the filing itself is the record of what was known on August 19, 2025.
Briefs are written by AI from the filing text and can contain mistakes — open the filing before acting on anything. Impact (1-5) and tone are the AI's reading of the filing for shareholders, not a price forecast. Not investment advice.