---
schema_version: "secwatch.filing_event.v1"
accession: "0000067716-23-000077"
form_type: "8-K/A"
ticker: "MDU"
cik: "0000067716"
company_name: "MDU RESOURCES GROUP INC"
filed_at: "2023-06-07T23:59:59+00:00"
generated_at: "2026-06-14T06:11:10.404393+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.5
calibrated_materiality_score: 0.5
confidence: "low"
source: SEC EDGAR
---

# MDU Resources files pro forma financials for Knife River spin-off; retains 10% stake

## Summary
- Spin-off of Knife River completed May 31, 2023; MDU stockholders received 1 KNF share per 4 MDU shares.
- MDU retained 10% of Knife River shares; intends to dispose via debt exchanges, distributions, or sales.
- Pro forma financials reclassify Knife River as discontinued operations for all periods presented.
- Pro forma data filed as Exhibit 99.1; actual numbers not provided in this summary.

## SEC filing metadata
- accession: 0000067716-23-000077
- form_type: 8-K/A
- ticker: MDU
- cik: 0000067716
- company_name: MDU RESOURCES GROUP INC
- filed_at: 2023-06-07T23:59:59+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.5
- calibrated_materiality_score: 0.5
- confidence: low
- sec_items: 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/67716/000006771623000077/0000067716-23-000077-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/67716/000006771623000077/mdu-20230530.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000067716-23-000077
- JSON: https://secwatch.observer/filing/0000067716-23-000077.json
- Plain text: https://secwatch.observer/filing/0000067716-23-000077.txt

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