| Name | Company Number | Date Appointed | Rating |
|---|---|---|---|
| 00465462 LIMITED | 00465462 | 09/04/1997 | One Red Flag |
| Aimtask Ltd | 02630144 | 09/04/1997 | Dissolved |
| Costain (Maidenhead) Ltd | 01174637 | 09/04/1997 | Dissolved |
| Costain Property Investments Ltd | 00594736 | 09/04/1997 | Dissolved |
| County & District Properties (Northern) Ltd | 00709459 | 09/04/1997 | Dissolved |
| Cpi Safe Felicia Ltd | 01970870 | 09/04/1997 | Dissolved |
| Elder Street (Holdings) Ltd | 02348490 | 22/04/1997 | Dissolved |
| Elder Street Properties Ltd | 02386480 | 22/04/1997 | Dissolved |
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| C. G. NOMINEES LIMITED | 01445212 | 09/04/1997 | 30/06/2001 | Dissolved |
| CLM ENGINEERING (OVERSEAS) LIMITED | 02992285 | 09/04/1997 | 30/06/2001 | Not Trading |
| COSTAIN ALCAIDESA LIMITED | 02042076 | 09/04/1997 | 30/06/2001 | Bronze |
| COSTAIN BUILDING & CIVIL ENGINEERING LIMITED | 01054232 | 09/04/1997 | 30/06/2001 | Gold |
| COSTAIN BUILDING PRODUCTS LIMITED | 00384636 | 09/04/1997 | 30/06/2001 | Dissolved |
| COSTAIN CIVIL ENGINEERING LIMITED | 02757907 | 09/04/1997 | 30/06/2001 | Amber |
| COSTAIN CONCRETE COMPANY LIMITED. | 00311582 | 09/04/1997 | 24/08/2000 | Dissolved |
| COSTAIN CONSTRUCTION LIMITED | 00563270 | 09/04/1997 | 30/06/2001 | Not Trading |
| COSTAIN ENGINEERING & CONSTRUCTION (OVERSEAS) LIMITED | 02440830 | 09/04/1997 | 30/06/2001 | Gold |
| COSTAIN ENGINEERING & CONSTRUCTION LIMITED | 02440829 | 09/04/1997 | 30/06/2001 | Gold |
| COSTAIN ENGINEERING LIMITED | 00426075 | 09/04/1997 | 30/06/2001 | Dissolved |
| COSTAIN GROUP PLC | 01393773 | 09/04/1997 | 30/06/2001 | Gold |
| COSTAIN INTERNATIONAL LIMITED | 00563275 | 09/04/1997 | 30/06/2001 | Amber |
| COSTAIN LIMITED | 00610201 | 09/04/1997 | 30/06/2001 | Silver |
| COSTAIN MANAGEMENT DESIGN LIMITED | 01599349 | 09/04/1997 | 30/06/2001 | Not Trading |
| COSTAIN OIL, GAS & PROCESS (OVERSEAS) LIMITED | 00583789 | 09/04/1997 | 30/06/2001 | Not Trading |
| COSTAIN OIL, GAS & PROCESS LIMITED | 00786418 | 09/04/1997 | 30/06/2001 | One Red Flag |
| COSTAIN PROCESS CONSTRUCTION LIMITED | 00590330 | 09/04/1997 | 30/06/2001 | Not Trading |
| COUNTY & DISTRICT PROPERTIES LIMITED | 00675355 | 09/04/1997 | 30/06/2001 | Silver |
| Clm Engineering Ltd | 02617370 | 09/04/1997 | 30/06/2001 | Dissolved |
| Costain Environmental Services Ltd | 02568196 | 09/04/1997 | 30/06/2001 | Dissolved |
| Costain Interiors Ltd | 03256841 | 09/04/1997 | 30/06/2001 | Dissolved |
| Costain International Management Ltd | 01747835 | 09/04/1997 | 24/08/2000 | Dissolved |
| Costain Marine International Ltd | 00214014 | 09/04/1997 | 24/08/2000 | Dissolved |
| Costain Mining Ltd | 00548252 | 09/04/1997 | 24/08/2000 | Dissolved |
| Costain Trade & Services Ltd | 02196822 | 09/04/1997 | 30/06/2001 | Dissolved |
| Costain Urban Enterprises Limited | 02522727 | 09/04/1997 | 30/06/2001 | Dissolved |
| FOUNDATION ENGINEERING LIMITED | 00610627 | 09/04/1997 | 31/05/2000 | Dissolved |
| M.L.M.Investments Limited | 00664334 | 09/04/1997 | 24/08/2000 | Dissolved |
| NATIONAL ROAD OPERATORS LIMITED | 02969113 | 09/04/1997 | 30/06/2001 | Dissolved |
| R. COSTAIN & SONS LIMITED | 00274452 | 09/04/1997 | 24/08/2000 | Not Trading |
| RENOWN INVESTMENTS (HOLDINGS) LIMITED | 00683698 | 09/04/1997 | 30/06/2001 | Gold |
| RICHARD COSTAIN LIMITED | 00274453 | 09/04/1997 | 30/06/2001 | Bronze |
| THE E J COOK SCD PARTNERSHIP LIMITED | 00472901 | 09/04/1997 | 30/06/2001 | Dissolved |
| WESTMINSTER PLANT CO. LIMITED | 00552140 | 09/04/1997 | 30/06/2001 | Not Trading |