| Relationships | Role | Relationship Start | Relationship End |
| Midamerican Corporation | Parent | 8/29/1989 | 7/15/1994 |
| Midamerican Corporation | Parent | 12/31/1974 | 8/28/1989 |
| Acquisitions & Mergers | Role | Assets | Acct Method | Type | Transaction Date |
| 9900 Building Corporation | Seller | Discontinued | 10/19/1989 |