| MARLEC ENGINEERING COMPANY LIMITED | Northants | 1978 | Small company accounts |
| ELECTRICAL CONSOLIDATED LIMITED | Tunbridge Wells | 1978 | Total exemption (full) |
| AUTOMATION CONTROLS (BELFAST) LIMITED | Belfast | 1978 | Total exemption (full) |
| KOMPRESS HOLDINGS LIMITED | Nottingham | 1978 | Total exemption (full) |
| WESSEX POWER TECHNOLOGY LIMITED | Winterborne Zelston | 1978 | Total exemption (full) |
| SEMCO MARITIME LIMITED | Westhill | 1978 | Full accounts |
| SCHNEIDER ELECTRIC LIMITED | — | 1978 | Full accounts |
| ERCO LIGHTING LIMITED | — | 1979 | Small company accounts |
| ALFATRONIX LIMITED | Ringwood Road | 1979 | Small company accounts |
| DANOR ENGINEERING LIMITED | London | 1979 | Unaudited abridged |
| MERTECH SWITCHBOARDS LIMITED | Luton | 1979 | Total exemption (full) |
| PB DESIGN AND DEVELOPMENTS LIMITED | Clevedon | 1979 | Full accounts |
| TOWERGLENS LIMITED | West Midlands | 1979 | Unaudited abridged |
| LINBURN TECHNOLOGY LIMITED | Edinburgh | 1979 | Total exemption (full) |
| VACUUM IMPREGNATED PRODUCTS LIMITED | Warrington | 1979 | Total exemption (full) |
| ASHGILL ELECTRONICS LIMITED | Larkhall | 1979 | Medium company accounts |
| THERMON (U.K.) LIMITED | Sunderland | 1979 | Small company accounts |
| ENSTO UK LIMITED | Birmingham | 1979 | Small company accounts |
| CLOSED CIRCUIT COOLING LIMITED | Telford | 1979 | Total exemption (full) |
| BOWER PRODUCTS LIMITED | Wembley | 1979 | Total exemption (full) |
| MORSON PROJECTS LIMITED | Salford | 1979 | Full accounts |
| UNITED INFRASTRUCTURE SYSTEMS (ICS) LIMITED | Warrington | 1979 | Audit-exempt subsidiary |
| PETER COPSEY ENGINEERING LIMITED | Aylesbury | 1979 | Total exemption (full) |
| APEX CABLES LIMITED | Durham City | 1979 | Full accounts |
| NUVONIC LIMITED | Slough | 1980 | Full accounts |
| YASKAWA UK LIMITED | Birmingham | 1980 | Full accounts |
| HELVAR LIMITED | London | 1980 | Full accounts |
| SOLO AUDIO ACCESSORIES LIMITED | Nottingham | 1980 | Total exemption (full) |
| APOLLO FIRE DETECTORS LIMITED | Hampshire | 1980 | Full accounts |
| WEBRO CABLES AND CONNECTORS LIMITED | Nottingham | 1980 | Full accounts |
| NATGRAPH LIMITED | Nottingham | 1980 | Small company accounts |
| HEADSTOCK DISTRIBUTION LIMITED | Halesowen | 1980 | Full accounts |
| ELECTRIC VEHICLE SYSTEMS LIMITED | Washington | 1980 | Total exemption (full) |
| SWARCO UK & IRELAND LTD | Basingstoke | 1980 | Full accounts |
| HEATSTAR LIMITED | Newport | 1980 | Total exemption (full) |
| CEPHOS ELECTRONIC CIRCUITS LIMITED | Swanley | 1980 | Total exemption (full) |
| ZEEFAX LIMITED | London | 1980 | Total exemption (full) |
| FARM ENERGY AND CONTROL SERVICES LIMITED | Oxford | 1980 | Total exemption (full) |
| METRO LIMITED | Leigh on Sea | 1980 | Total exemption (full) |
| KALESTEAD LIMITED | Braintree | 1980 | Total exemption (full) |
| ARDEN CONTROLS & ELECTRICAL LIMITED | New Mills | 1980 | Unaudited abridged |
| SCREENBOND LIMITED | Baldock | 1980 | Total exemption (full) |
| FANTASTIC LIGHTING LIMITED | Erith | 1980 | Total exemption (full) |
| APOLLO LIGHTING LIMITED | Leeds | 1980 | Total exemption (full) |
| WELTECH LIMITED | Huntington | 1980 | Total exemption (full) |
| MEECH STATIC ELIMINATORS LIMITED | Witney | 1980 | Full accounts |
| TRATOS (UK) LIMITED | Prescot | 1980 | Group accounts |
| AUTOLUX LIMITED | Yeadon | 1980 | Total exemption (full) |
| ISOTHERMAL TECHNOLOGY LIMITED | Merseyside | 1980 | Medium company accounts |
| ARMOUR HOME ELECTRONICS LIMITED | Bishop’s Stortford | 1980 | Full accounts |
| TEMPCON INSTRUMENTATION LIMITED | Arundel | 1980 | Total exemption (full) |
| TRANSFORMER MANUFACTURING COMPANY LIMITED | Mill Lane Maldon | 1981 | Total exemption (full) |
| PETREL LIMITED | Birmingham | 1981 | Audit-exempt subsidiary |
| T. & R. TEST EQUIPMENT LIMITED | Surrey | 1981 | Small company accounts |
| AEROTECH, LIMITED | Reading | 1981 | Full accounts |
| VICON INDUSTRIES LIMITED | Southampton | 1981 | Medium company accounts |
| TRICOOL LIMITED | Redcar | 1981 | Total exemption (full) |
| ATL TRANSFORMERS LIMITED | Middleton | 1981 | Total exemption (full) |
| GS YUASA BATTERY MANUFACTURING UK LIMITED | Ebbw Vale | 1981 | Full accounts |
| HIRST MAGNETIC INSTRUMENTS LIMITED | Falmouth | 1981 | Total exemption (full) |