1 Exhibit 21 SUBSIDIARIES OF NTL INCORPORATED All of the corporations listed below were organized in the United Kingdom. Andover Cablevision Limited Anglia Cable Communications Limited Berkhamsted Properties & Building Contractors Limited Bracknell Cable TV Limited Cable Television Limited Cable Thames Valley Limited CableTel Cardiff Limited CableTel Central Hertfordshire Limited CableTel Glasgow CableTel Hertfordshire Limited CableTel Herts and Beds Limited CableTel Investments Limited CableTel Kirklees CableTel Limited CableTel Newport CableTel North Bedfordshire Limited CableTel Northern Ireland Limited CableTel Scotland Limited CableTel South Wales Limited CableTel Surrey and Hampshire Limited CableTel Telecom Supplies Limited CableTel (UK) Limited CableTel West Glamorgan Limited CableTel West Riding Limited Cambridge Cable Limited Cambridge Cable Services Limited Cambridge Holding Company Limited CCL Corporate Communication Services Limited Chiltern Cable Limited Columbia Management Limited ComTel Limited ComTel Cable Services Limited ComTel Coventry Limited Credit-Track Debt Recovery Limited Digital Television Network Limited DTELS Limited East Coast Cable Limited Enablis Limited Heartland Cablevision (UK) Limited Heartland Cablevision II (UK) Limited Herts Cable Limited 2 Lichfield Cable Communications Limited Maza Limited Metro Hertfordshire Limited Metro South Wales Limited National Transcommunications LimitNorthampton Cable Television Limited NTL Communications Limited NTL Darlington Limited NTL Digital Limited NTL Digital Radio Limited NTL Group Limited NTL Insurance Limited NTL Internet Limited NTL Investment Holdings Limited NTL Limited NTL Networks Limited NTL Systems Limited NTL Teesside Limited NTL Telecom Services Limited (formerly Eastern Group Telecoms Ltd) NTL Trustees Limited Oxford Cable Limited Premium TV Limited Prospectre Limited Secure Backup Systems Limited South Yorkshire Cablevision (UK) Limited Southern East Anglia Cable Limited Stafford Communications Limited Swindon Cable Limited Tamworth Cable Communications Limited Vision Networks Services UK Limited Wessex Cable Limited XL Debt Recovery Agency Limited All of the corporations listed below were incorporated in Delaware except where otherwise noted: Bearsden Nominees, Inc. CableTel Programming, Inc. CableTel Ventures Limited Cellular Paging, Inc. L.D. Data, Inc. NTL (UK) Group, Inc. NTL Digital (US), Inc. NTL International Services, Inc. OCOM Corporation OCOM New York, Inc. All of the companies listed below were formed in Bermuda except where otherwise noted: Comcast UK Cable Partners Limited Comcast UK Consulting, Inc. (US Virgin Islands company) 2 3 Comcast UK Programming Limited Comcast UK Holdings Limited NTL (Bermuda) Limited 3 4 All of the corporations listed below were organized in the United Kingdom. Diamond Cable Acquisitions Limited Diamond Cable (Bassetlaw) Limited Diamond Cable (Burton-upon-Trent) Limited Diamond Cable (Chesterfield) Limited Diamond Cable Communications plc Diamond Cable Communications (UK) Limited Diamond Cable Construction Limited Diamond Cable CPE Limited Diamond Cable (Grantham) Limited Diamond Cable (Grimclee) Limited Diamond Cable (Hinckley) Limited Diamond Cable (Leicester) Limited Diamond Cable (Lincoln) Limited Diamond Cable (Lincolnshire) Limited Diamond Cable (Mansfield) Limited Diamond Cable (Melton Mowbray) Limited Diamond Cable (Newark-on-Trent) Limited Diamond Cable (Ravenshead) Limited Diamond Cable (Vale of Belvoir) Limited Diamond Holdings plc Diamond Visual Communications Limited East Midlands Cable Communications Limited East Midlands Cable Group Limited East Midlands Cable Holdings Limited Jewel Holdings Limited LCL Cable (Holdings) Limited LCL Telephones Limited 4