| Relationships | Role | Relationship Start | Relationship End |
| Citigroup Capital Partners I Gp Ii Corp. | Parent | 6/14/2000 | |
| Citigroup Capital Partners I (Master Fund), Lp | Subsidary | 11/30/2000 | |
| Citigroup Capital Partners I Energy, Llc | Subsidary | 2/1/2005 | 5/23/2011 |