Exhibit 21(a) MATERIAL SUBSIDIARIES OF TXU EUROPE LIMITED TXU Europe Group plc Eastern Electricity plc TXU EUROPE POWER LIMITED Anglian Power Generators Limited Eastern Generation Services Limited Eastern Generation Research limited Eastern Merchant Generation Limited Eastern Merchant Properties Limited Eastern Renewable Generation Limited Eastern Gas Generation Maintenance Limited Peterborough Power Limited Shotton Combined Heat Limited Nedalo (UK) Ltd BG Cogen Limited Citigen (London) Limited Eastern Group Finance Limited EASTERN POWER AND ENERGY TRADING LIMITED Eastern Natural Gas (Trading) Limited Eastern Natural Gas (Offshore) Limited Eastern Ten Limited Eastern Power and Energy Trading Poland Sp zoo