Exhibit 21-1



Exelon Corporation Subsidiary Listing



|                                                |  |                         
|----------------------------------------------- |  | ------------------------
|Affiliate                                       |  | Jurisdiction ofFormation
|                                                |  | Pennsylvania            
|Adwin (Schuylkill) Cogeneration, Inc.           |  | Pennsylvania            
|Adwin Realty Company                            |  | Pennsylvania            
|AllEnergy Gas & Electric Marketing Company, LLC |  | Delaware                
|Ambassador II Joint Venture                     |  | Pennsylvania            
|AmerGen Clinton NQF, LLC                        |  | Nevada                  
|AmerGen Consolidation, LLC                      |  | Nevada                  
|AmerGen Energy Company, LLC                     |  | Delaware                
|AmerGen Oyster Creek NQF, LLC                   |  | Nevada                  
|AmerGen TMI NQF, LLC                            |  | Nevada                  
|ATNP Finance Company                            |  | Delaware                
|Bradford Associates                             |  | Pennsylvania            
|Braidwood 1 NQF, LLC                            |  | Nevada                  
|Braidwood 2 NQF, LLC                            |  | Nevada                  
|Byron 1 NQF, LLC                                |  | Nevada                  
|Byron 2 NQF, LLC                                |  | Nevada                  
|Cenesco Company, LLC                            |  | Delaware                
|ComEd Financing II                              |  | Delaware                
|ComEd Financing III                             |  | Delaware                
|ComEd Funding, LLC                              |  | Delaware                
|ComEd Transitional Funding Trust                |  | Delaware                
|Commonwealth Edison Company                     |  | Illinois                
|Commonwealth Edison Company of Indiana, Inc.    |  | Indiana                 
|Concomber, Ltd.                                 |  | Bermuda                 
|Conemaugh Fuels, LLC                            |  | Delaware                
|Dresden 1 NQF, LLC                              |  | Nevada                  
|Dresden 2 NQF, LLC                              |  | Nevada                  
|Dresden 3 NQF, LLC                              |  | Nevada                  
|ECP Telecommunications Holdings, LLC            |  | Delaware                
|ECPH, LLC                                       |  | Delaware                
|Edison Development Canada Inc.                  |  | Ontario                 
|Edison Finance Partnership                      |  | Canada                  
|EGW Meter Services, LLC                         |  | Delaware                
|EIS Engineering, Inc.                           |  | Delaware                
|EIS Investments, LLC                            |  | Delaware                
|ENEH Services, LLC                              |  | Delaware                
|ETT Boston, Inc.                                |  | Delaware                
|ETT Canada, Inc.                                |  | New Brunswick           
|ETT North America, Inc.                         |  | Delaware                
|Exelon Allowance Management Company, LLC        |  | Delaware                
|Exelon AOG Holding # 1, Inc.                    |  | Delaware                
|Exelon AOG Holding # 2, Inc.                    |  | Delaware                
|Exelon Business Services Company                |  | Pennsylvania            
|Exelon Capital Trust I                          |  | Delaware                
|Exelon Capital Trust II                         |  | Delaware                
|Exelon Capital Trust III                        |  | Delaware                
|Exelon Edgar, LLC                               |  | Delaware                



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|                                                        |  |             
|------------------------------------------------------- |  | ------------
|Exelon Energy Company                                   |  | Delaware    
|Exelon Energy Delivery Company, LLC                     |  | Delaware    
|Exelon Enterprises Company, LLC                         |  | Pennsylvania
|Exelon Enterprises Investments, Inc.                    |  | Delaware    
|Exelon Enterprises Management, Inc.                     |  | Pennsylvania
|Exelon Framingham Development, LLC                      |  | Delaware    
|Exelon Framingham, LLC                                  |  | Delaware    
|Exelon Generation Company, LLC                          |  | Pennsylvania
|Exelon Generation Consolidation, LLC                    |  | Nevada      
|Exelon Generation Finance Company, LLC                  |  | Delaware    
|Exelon Generation International, Inc.                   |  | Pennsylvania
|Exelon Hamilton, LLC                                    |  | Delaware    
|Exelon Investment Holdings, LLC                         |  | Illinois    
|Exelon New Boston, LLC                                  |  | Delaware    
|Exelon New England Development, LLC                     |  | Delaware    
|Exelon New England Holdings, LLC                        |  | Delaware    
|Exelon New England Power Marketing, Limited Partnership |  | Delaware    
|Exelon Peaker Development General, LLC                  |  | Delaware    
|Exelon Peaker Development Limited, LLC                  |  | Delaware    
|Exelon PowerLabs, LLC                                   |  | Pennsylvania
|Exelon Services, Inc.                                   |  | Delaware    
|Exelon SHC, Inc.                                        |  | Delaware    
|Exelon Synfuel I, LLC                                   |  | Delaware    
|Exelon Synfuel II, LLC                                  |  | Delaware    
|Exelon Synfuel III, LLC                                 |  | Delaware    
|Exelon Thermal Holdings, Inc.                           |  | Delaware    
|Exelon Ventures Company, LLC                            |  | Delaware    
|Exelon West Medway Development, LLC                     |  | Delaware    
|Exelon West Medway Expansion, LLC                       |  | Delaware    
|Exelon West Medway, LLC                                 |  | Delaware    
|Exelon Wyman, LLC                                       |  | Delaware    
|Ex-FM, Inc.                                             |  | New York    
|Ex-FME, Inc.                                            |  | Delaware    
|Ex-FMEC, Inc.                                           |  | Delaware    
|ExTel Corporation, LLC                                  |  | Delaware    
|ExTex LaPorte Limited Partnership                       |  | Texas       
|ExTex Marketing, LLC                                    |  | Delaware    
|ExTex Power, LP                                         |  | Delaware    
|ExTex Retail Services Company, LLC                      |  | Delaware    
|F & M Holdings Company, LLC                             |  | Delaware    
|Henderson Ambassador Associates                         |  | Pennsylvania
|Horizon Energy Company                                  |  | Pennsylvania
|II Services, Inc.                                       |  | Delaware    
|InfraSource Field Services LLC                          |  | Oklahoma    
|Keystone Fuels, LLC                                     |  | Delaware    
|LaSalle 1 NQF, LLC                                      |  | Nevada      
|LaSalle 2 NQF, LLC                                      |  | Nevada      
|Limerick 1 NQF, LLC                                     |  | Nevada      
|Limerick 2 NQF, LLC                                     |  | Nevada      
|NEWCOSY, Inc.                                           |  | Delaware    
|NEWCOTRA, Inc.                                          |  | Delaware    
|North America Power Services, Inc.                      |  | Delaware    



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|                                                    |  |               
|--------------------------------------------------- |  | --------------
|Northwind Boston, LLC                               |  | Massachusetts 
|Northwind Thermal Technologies Canada, Inc.         |  | New Brunswick 
|Northwind Windsor                                   |  | New Brunswick 
|Nuclear US Holdings, Inc.                           |  | Delaware      
|Nuclear US Investments, LLC                         |  | Delaware      
|Nuclear, Limited Partnership                        |  | Delaware      
|NuStart Energy Development, LLC                     |  | Delaware      
|Oldco VSI, Inc.                                     |  | Delaware      
|OSP Servicios S.A. de C.V.                          |  | Mexico        
|PeachBottom 1 NQF, LLC                              |  | Nevada        
|PeachBottom 2 NQF, LLC                              |  | Nevada        
|PeachBottom 3 NQF, LLC                              |  | Nevada        
|PEC Financial Services, LLC                         |  | Pennsylvania  
|PECO Energy Capital Corp.                           |  | Delaware      
|PECO Energy Capital Trust III                       |  | Delaware      
|PECO Energy Capital Trust IV                        |  | Delaware      
|PECO Energy Capital Trust V                         |  | Delaware      
|PECO Energy Capital Trust VI                        |  | Delaware      
|PECO Energy Capital, LP                             |  |               
|PECO Energy Company                                 |  | Pennsylvania  
|PECO Energy Power Company                           |  | Pennsylvania  
|PECO Energy Transition Trust                        |  | Delaware      
|PECO Wireless, LP                                   |  | Delaware      
|Penesco Company, LLC                                |  | Delaware      
|Power Tree Carbon Company, LLC                      |  |               
|Quad Cities 1 NQF, LLC                              |  | Nevada        
|Quad Cities 2 NQF, LLC                              |  | Nevada        
|Rand-Bright Corporation                             |  | Wisconsin     
|Salem 1 NQF, LLC                                    |  | Nevada        
|Salem 2 NQF, LLC                                    |  | Nevada        
|Scherer Holdings 1, LLC                             |  | Delaware      
|Scherer Holdings 2, LLC                             |  | Delaware      
|Scherer Holdings 3, LLC                             |  | Delaware      
|Sithe Latin American Holdings, Ltd.                 |  | Cayman Islands
|Sithe Overseas Power Services, Ltd.                 |  | Virgin Islands
|Sithe PARDO Holdings, Ltd.                          |  | Cayman Islands
|Sithe Tamuin Energy Services II, S. de R.L. de C.V. |  | Mexico        
|Sithe Tamuin Energy Services, S. de R.L. de C.V.    |  | Mexico        
|Sithe Tamuin Investments II, S. de R.L. de C.V.     |  | Mexico        
|Sithe Tamuin Investments, S. de R.L. de C.V.        |  | Mexico        
|Southeast Chicago Energy Project, LLC               |  | Delaware      
|Spruce Equity Holdings, L.P.                        |  | Delaware      
|Spruce Holdings G.P. 2000, LLC                      |  | Delaware      
|Spruce Holdings L.P. 2000, LLC                      |  | Delaware      
|Spruce Holdings Trust                               |  | Delaware      
|Susquehanna Electric Company                        |  | Maryland      
|Susquehanna Power Company                           |  | Maryland      
|T.H. Green Electric Co., Inc.                       |  | New York      
|Tamuin Development Services, S. de R.L. de C.V.     |  | Mexico        
|Tamuin Energy Management Services II, Inc.          |  | Delaware      
|Tamuin Energy Management Services, Inc.             |  | Delaware      
|Tamuin Holdings A, LLC                              |  | Delaware      



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|                                            |  |         
|------------------------------------------- |  | --------
|Tamuin Holdings II, LLC                     |  | Delaware
|Tamuin Holdings III, LLC                    |  | Delaware
|Tamuin Holdings, LLC                        |  | Delaware
|Tamuin International Finance II, LLC        |  | Delaware
|Tamuin International Finance, LLC           |  | Delaware
|Tamuin International, Inc.                  |  | Delaware
|Tamuin Mexican Business Trust               |  | Mexico  
|Tamuin Mexican Business Trust II            |  | Mexico  
|TEG Holdings, LLC                           |  | Delaware
|Termoelectrica del Golfo, S. de RL. de C.V. |  | Mexico  
|Termoelectrica Penoles, S. de R.L. de C.V.  |  | Mexico  
|Texas Ohio Gas, Inc.                        |  | Texas   
|The Proprietors of the Susquehanna Canal    |  | Maryland
|UII, LLC                                    |  | Illinois
|Unicom Assurance Company, Ltd.              |  | Bermuda 
|Unicom Power Marketing, Inc.                |  | Delaware
|URI, LLC                                    |  | Illinois
|Wansley Holdings 1, LLC                     |  | Delaware
|Wansley Holdings 2, LLC                     |  | Delaware
|Zion 1 NQF, LLC                             |  | Nevada  
|Zion 2 NQF, LLC                             |  | Nevada