Exhibit 21(a)

ENERGY FUTURE HOLDINGS CORP.

SUBSIDIARY HIERARCHY

Effective March 29, 2008



|                                           |  |             
|------------------------------------------ |  | ------------
|                                           |  | Jurisdiction
|Energy Future Holdings Corp.               |  | Texas       
|Energy Future Competitive Holdings Company |  | Texas       
|Texas Competitive Electric Holdings LLC    |  | Delaware    
|TCEH Finance, Inc.                         |  | Delaware    
|Generation MT Company LLC                  |  | Delaware    
|EFH CG Holdings Company LP1                |  | Texas       
|Luminant Holding Company LLC               |  | Delaware    
|Luminant Energy Company LLC                |  | Texas       
|Luminant ET Services Company               |  | Texas       
|Luminant Energy Trading California Company |  | Texas       
|Luminant Energy Trading Canada Limited     |  | Canada      
|EFH CG Holdings Company LP2                |  | Texas       
|Luminant Energy Services Company           |  | Texas       
|Luminant Generation Company LLC            |  | Texas       
|Valley NG Power Company LLC                |  | Texas       
|Luminant Renewables Company LLC            |  | Texas       
|Fuelco LLC3                                |  | Delaware    
|EFH CG Holdings Company LP4                |  | Texas       
|Generation SVC Company                     |  | Texas       
|Luminant Power Services Company            |  | Delaware    
|Big Brown 3 Power Company LLC              |  | Texas       
|Big Brown Power Company LLC                |  | Texas       
|Collin Power Company LLC                   |  | Delaware    
|DeCordova Power Company LLC                |  | Texas       
|Lake Creek 3 Power Company LLC             |  | Texas       
|Martin Lake 4 Power Company LLC            |  | Texas       
|Monticello 4 Power Company LLC             |  | Texas       
|Morgan Creek 7 Power Company LLC           |  | Texas       
|Oak Grove Management Company LLC           |  | Delaware    
|Oak Grove Power Company LLC                |  | Texas       
|Sandow Power Company LLC                   |  | Texas       
|Tradinghouse 3 & 4 Power Company LLC       |  | Texas       
|Tradinghouse Power Company LLC             |  | Texas       
|Valley Power Company LLC                   |  | Texas       
|Luminant Mining Services Company           |  | Delaware    
|Big Brown Lignite Company LLC              |  | Texas       
|Luminant Big Brown Mining Company LLC      |  | Texas       
|Luminant Mining Company LLC                |  | Texas       
|Oak Grove Mining Company LLC               |  | Texas       
|Luminant Mineral Development Company LLC   |  | Texas       
|NCA Resources Development Company LLC      |  | Texas       
|Wichita/Victory Avenue LLC                 |  | Texas       
|TXU Energy Retail Company LLC              |  | Texas       
|TXU Retail Services Company                |  | Delaware    
|EFH CG Holdings Company LP5                |  | Texas       
|TXU SESCO Company LLC                      |  | Texas       
|TXU SESCO Energy Services Company          |  | Texas       
|TXU Energy Solutions Company LLC           |  | Texas       
|TXU Chilled Water Solutions Company        |  | Texas       
|TXU SEM Company                            |  | Texas       
|TXU Energy Retail Management Company LLC   |  | Delaware    



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|                                                                     |  |                     
|-------------------------------------------------------------------- |  | --------------------
|                                                                     |  | Jurisdiction        
|Energy Future Intermediate Holding Company LLC                       |  | Delaware            
|Oncor Electric Delivery Holdings Company LLC                         |  | Delaware            
|Oncor Electric Delivery Company LLC                                  |  | Delaware            
|Oncor Electric Delivery Transition Bond Company LLC                  |  | Delaware            
|EFH CG Holdings Company LP6                                          |  | Texas               
|Oncor License Holdings Company LLC                                   |  | Texas               
|Oncor Communications Holdings Company LLC                            |  | Delaware            
|EFH Corporate Services Company                                       |  | Texas               
|Dallas Power and Light Company Inc. (name holder entity only)        |  | Texas               
|Lone Star Energy Company Inc. (name holder entity only)              |  | Texas               
|Lone Star Pipeline Company Inc. (name holder entity only)            |  | Texas               
|Southwestern Electric Service Company Inc. (name holder entity only) |  | Texas               
|Texas Electric Service Company Inc. (name holder entity only)        |  | Texas               
|Texas Energy Industries Company Inc. (name holder entity only)       |  | Texas               
|Texas Power and Light Company Inc. (name holder entity only)         |  | Texas               
|Texas Utilities Company Inc. (name holder entity only)               |  | Texas               
|Texas Utilities Electric Company Inc. (name holder entity only)      |  | Texas               
|TXU Electric Company Inc. (name holder entity only)                  |  | Texas               
|EFH CG Management Company LLC                                        |  | Texas               
|EFH CG Holdings Company LP7                                          |  | Texas               
|DFW Midstream Services LLC                                           |  | Texas               
|Generation Development Company LLC                                   |  | Delaware            
|InfrastruX Energy Services BPL LLC                                   |  | Delaware            
|NCA Development Company LLC                                          |  | Texas               
|EFH Industries Company LLC                                           |  | Delaware            
|EFH Properties Company                                               |  | Texas               
|Communications License Holdings I Inc.                               |  | Texas               
|EFH Investment Company                                               |  | Texas               
|Basic Resources Inc.                                                 |  | Texas               
|TXU Receivables Company                                              |  | Delaware            
|EFH CC Holdings Company LLC                                          |  | Texas               
|Current Communications Group LLC8                                    |  | Delaware            
|EFH Vermont Insurance Company                                        |  | Vermont             
|LSGT Gas Company LLC                                                 |  | Texas               
|LSGT Processing Company                                              |  | Texas               
|Lone Star Energy Services, Inc                                       |  | Texas               
|ENS Holdings I, Inc.                                                 |  | Texas               
|ENS Holdings II, Inc.                                                |  | Texas               
|ENS Holdings Limited Partnership9                                    |  | Texas               
|LSGT SACROC, Inc.10                                                  |  | Texas               
|LSGT Finance (II), Inc.                                              |  | Texas               
|LSGT House Inc.                                                      |  | Texas               
|Enserch Finance N.V.                                                 |  | Netherlands Antilles
|LSGT International Investments Limited                               |  | Delaware            
|Humphreys & Glasgow Limited                                          |  | United Kingdom      
|EEC Holdings Inc                                                     |  | Nevada              
|EECI, Inc.                                                           |  | Nevada              
|Ebasco Services of Canada, Ltd                                       |  | Canada              
|EFH CG Holdings Company LP11                                         |  | Texas               
|EFH Australia (No. 2) Holdings Company                               |  | Delaware            
|EFH FS Holdings Company                                              |  | Delaware            
|TXU International Holdings Limited                                   |  | United Kingdom      
|TXU Finance (No. 3) Limited                                          |  | United Kingdom      
|TXU Europe Limited                                                   |  | United Kingdom      
|TXU Europe CP Inc                                                    |  | Delaware            
|TXU Eastern Finance (A) Ltd                                          |  | United Kingdom      
|TXU Eastern Finance (B) Ltd                                          |  | United Kingdom      
|TXU Eastern Funding Company12                                        |  | United Kingdom      



---

|                                     |  |               
|------------------------------------ |  | --------------
|                                     |  | Jurisdiction  
|EFH Finance (No. 2) Holdings Company |  | Delaware      
|TXU Finance (No. 2) Limited13        |  | United Kingdom
|TXU Acquisitions Limited             |  | United Kingdom
|TXU Energy Group Limited             |  | United Kingdom
|TXU Europe Group PLC                 |  | United Kingdom
|Energy Holdings (No. 3) Limited      |  | United Kingdom



|1 | 0.3% ownership interest
|- | -----------------------

|2 | 22% ownership interest
|- | ----------------------

|3 | 92% ownership interest
|- | ----------------------

|4 | 2.4% ownership interest
|- | -----------------------

|5 | 28.4% ownership interest
|- | ------------------------

|6 | 19.5% ownership interest
|- | ------------------------

|7 | 21.5% ownership interest
|- | ------------------------

|8 | 25.874% ownership interest
|- | --------------------------

|9 | 99% owned by ENS Holdings II, Inc. and 1% owned by ENS Holdings
I, Inc.
|- | -----------------------------------------------------------------------

|10 | 0.35% owned by ENS Holdings Limited Partnership and 99.65% owned
by LSGT Finance (II), Inc.
|-- | -------------------------------------------------------------------------------------------

|11 | 5.9% ownership interest
|-- | -----------------------

|12 | 50% owned by TXU Eastern Finance (A) Ltd and 50% owned by TXU
Eastern Finance (B) Ltd
|-- | -------------------------------------------------------------------------------------

|13 | 10% owned by EFH Finance (No. 2) Holdings Company and 90% owned
by TXU Europe Limited
|-- | -------------------------------------------------------------------------------------