Exhibit 21.1

Exelon Corporation Subsidiary Listing



|                                                        |  |                         
|------------------------------------------------------- |  | ------------------------
|Affiliate                                               |  | Jurisdiction ofFormation
|Adwin Realty Company                                    |  | Pennsylvania            
|AllEnergy Gas & Electric Marketing Company, LLC         |  | Delaware                
|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                
|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                 
|Conemaugh Fuels, LLC                                    |  | Delaware                
|Dresden 1 NQF, LLC                                      |  | Nevada                  
|Dresden 2 NQF, LLC                                      |  | Nevada                  
|Dresden 3 NQF, LLC                                      |  | Nevada                  
|Edison Development Canada Inc.                          |  | Ontario                 
|Edison Finance Partnership                              |  | Canada                  
|EIS Engineering, Inc.                                   |  | Delaware                
|ENEH Services, LLC                                      |  | Delaware                
|ETT Boston, Inc.                                        |  | Delaware                
|ETT Canada, Inc.                                        |  | New Brunswick           
|ETT North America, Inc.                                 |  | Delaware                
|Exelon AOG Holding # 1, Inc.                            |  | Delaware                
|Exelon AOG Holding # 2, Inc.                            |  | Delaware                
|Exelon Business Services Company                        |  | Pennsylvania            
|Exelon Business Services Company, LLC                   |  | Delaware                
|Exelon Capital Trust I                                  |  | Delaware                
|Exelon Capital Trust II                                 |  | Delaware                
|Exelon Capital Trust III                                |  | Delaware                
|Exelon Edgar, LLC                                       |  | Delaware                
|Exelon Energy Company                                   |  | Delaware                
|Exelon Energy Delivery Company, LLC                     |  | Delaware                
|Exelon Enterprises Company, LLC                         |  | 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 Nuclear Security, LLC                            |  | Delaware                
|Exelon Nuclear Texas Holdings, LLC                      |  | Delaware                
|Exelon Peaker Development General, LLC                  |  | Delaware                
|Exelon Peaker Development Limited, LLC                  |  | Delaware                
|Exelon PowerLabs, LLC                                   |  | Pennsylvania            
|Exelon Mechanical, 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                





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|                                            |  |               
|------------------------------------------- |  | --------------
|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 Retail Services Company, LLC          |  | Delaware      
|F & M Holdings Company, LLC                 |  | Delaware      
|Horizon Energy Company                      |  | Pennsylvania  
|II Services, Inc.                           |  | Delaware      
|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      
|North America Power Services, Inc.          |  | Delaware      
|Northwind Thermal Technologies Canada, Inc. |  | New Brunswick 
|Nuclear US Holdings, LLC                    |  | 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                     |  | Delaware      
|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              |  | Delaware      
|Quad Cities 1 NQF, LLC                      |  | Nevada        
|Quad Cities 2 NQF, LLC                      |  | Nevada        
|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 Overseas Power Services, Ltd.         |  | Virgin Islands
|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 International, Inc.                  |  | Delaware      
|TEG Holdings, LLC                           |  | Delaware      
|Texas Ohio Gas, Inc.                        |  | Texas         
|The Proprietors of the Susquehanna Canal    |  | Maryland      
|UII, LLC                                    |  | Illinois      
|URI, LLC                                    |  | Illinois      
|Wansley Holdings 1, LLC                     |  | Delaware      
|Wansley Holdings 2, LLC                     |  | Delaware      
|Zion 1 NQF, LLC                             |  | Nevada        
|Zion 2 NQF, LLC                             |  | Nevada