Company Index
- Oakmoor - London
- Oakmount Control Systems Ltd - Plymouth
- Oakwade Ltd - Hartlepool
- Oasis Ltd - Slough
- Oast House Marketing - Ashford
- OBD Systems Ltd - Trowbridge
- Obducat Camscan Ltd - Cambridge
- Observant Electronics Ltd - Melksham
- Ocean Grove Developments Ltd - Reading
- OCS Group UK Ltd - Manchester
- Octaveward Ltd - Darwen
- Octec Ltd - Bracknell
- ODU (UK) Ltd - Loughborough
- OEM Automatic Ltd - Leicester
- Oerlikon Leybold Vacuum UK Ltd - Chessington
Offshore Electronics Ltd - Guernsey- Offshore Product Services Ltd - Lincoln
- Ogier Electronics Ltd - St Albans
- Ohgon Electronics - Canvey Island
- OHM UK Ltd - Knutsford
- Ohmega Ltd - New Milton
- Oilstore Ltd - Southampton
- OK International Ltd - Chandlers Ford
- OKI (UK) Ltd - Cumbernauld
- OKI Europe Ltd - Egham
- OKI Printing Solutions Ltd - Slough
- OKW Enclosures Ltd - Fareham
- Oldham Lighting Ltd - Bookham
- Ole Wolff Electronics Ltd - Bedford
- Olmec Advanced Materials Ltd - Sheffield
- Olson Electronics Ltd - Stanmore
- Olympic Gymnasium Services - Banbury
- Olympus Automation Ltd - Peterborough
- Olympus NDT UK Ltd - Rotherham
- Olympus Optical Co (UK) Ltd - London
- Omar Skinner and Sons Partnership - Bracknell
- Omeg Ltd - East Grinstead
- Omega Calibration Laboratories - Chesterfield
- Omega Engineering Ltd - Manchester
- Omega Research Ltd - Ely
- Omega Wire Ltd - Brierley Hill
- Omi Monitor Services - Stevenage
- Omicron Electronics UK Ltd - Stafford
- Omicron Ltd - Ilford
- Omiran Ltd - Bury St Edmunds
- Omitec Instrumentation Ltd - Devizes
- Omni Sensors and Transmitters Ltd - Coventry
- Omnia HV Rail Ltd - Uttoxeter
- Omniflex Ltd - Stockport
- Omnitest Ltd - Wimborne
- Omron Electronics Ltd - Milton Keynes
- On Board SM Assembly Ltd - Darwen
- On Time Communications Ltd - High Wycombe
- Onboard Electronics Ltd - Aldermaston
- Onclick Ltd - Tonbridge
- One North East Development Board - Newcastle upon Tyne
- One Way Circuits Ltd - Norwich
- Onelan - Henley on Thames
- OnSpec Oscillators Ltd - Nuneaton
- Onyx Holdings Ltd - South Petherton
- OP-TEC Systems Ltd - Telford
- Opal Group Ltd - Sevenoaks
- Opas IT Ltd - London
- Open Networks Engineering Ltd - Bishops Stortford
- Openhouse Europe Ltd - Newcastle under Lyme
- Openings - Bournemouth
- Opsol UK Ltd - Cramlington
- Optex (Europe) - Maidenhead
- Optic Lighting Ltd - Nelson
- Optical Filters Ltd - Thame
- Optical Technology Training Ltd - Skipton
- Optical Test and Calibration Ltd - Bradford
- Optical Tools for Industry - Ruthin
- Opticon Ltd - Luton
- Opticus - Glasgow
- Optikinetics Ltd - Luton
- Optilan (UK) Ltd - Kenilworth
- Optima Research Ltd - Stansted
- Optime Lighting Ltd - Hitchin
- Optimim - Llandysul
- Option Technologies Europe Ltd - Rossendale
- OptiSense Ltd - Horsham
- Optivision (Yorkshire) Ltd - Ossett
- Optocap Ltd - Livingston
- Optoelectronic Manufacturing Corporation (UK) Ltd - Redruth
- Optoma Europe Ltd - Watford
- Optomark - Tiverton
- OptoSci Ltd - Glasgow
- Optosource - Ulverston
- Opulent UK Ltd - Worthing
- ORA Lighting - London
- Oracle Components Ltd - Harlow
- Oracle Vision Ltd - Pontefract
- Orange Instruments Ltd - Northampton
- Orbik Electronics Ltd - Aldridge
- Orbit Research Ltd - Bradford
- Orbital Epos Systems Ltd - Warminster
- Orchard Electronic - Hailsham
- Orchard Process Controls - Brixham
- Oriel Systems Ltd - Chippenham
- Origin Precision Mouldings Ltd - East Kilbride
- Orion Devices Ltd - Norwich
- Orion Electric (UK) Ltd - Port Talbot
- Orion Media Marketing Ltd - Brentford
- Orion Projects Ltd - Saltash
- Orion Storage Solutions Ltd - Abertillery
- Orion Systems Ltd - Ashby de la Zouch
- Orlight Ltd - Potters Bar
- Ormiston Wire Ltd - Isleworth
- Orscheln Europe - Rugby
- Osborne and Collins - Walton on Thames
- Osborne Precision Sheet Metal Ltd - Hungerford
- Osco Ltd - Bletchley
- OSEC 2000 Ltd - Ipswich
- Oshino Lamps (UK) Ltd - Nottingham
- Osmor Products Ltd - Hassocks
- Ossett Industrial Projects Ltd - Wakefield
- Oticon Ltd - Hamilton
- Otodynamics Ltd - Hatfield
- Otter Controls Ltd - Buxton
- Out Board (Sheriff Technology Ltd) - Hitchin
- Outram Research Ltd - Chichester
- Outsource Electronics Ltd - Havant
- Oval Automation - Bognor Regis
- Oval Products Ltd - Surbiton
- Ovation Systems Ltd - Thame
- Overseas Medical Supplies Ltd - London
- Oxbridge Monitoring Ltd - Banbury
- Oxford Applied Research Ltd - Witney
- Oxford Diesels Ltd - Abingdon
- Oxford Electronics - Oxford
- Oxford Electronics Ltd - Alton
- Oxford Instruments NanoAnalysis - High Wycombe
- Oxford Instruments Plasma Technology - Bristol
- Oxford Instruments Superconductivity - Abingdon
- Oxford Lasers Ltd - Didcot
- Oxford Semiconductors Ltd - Abingdon
- Oxford Sound Co Ltd The - Chipping Norton
- Oxley Developments Co Ltd - Components Division - Barrow in Furness
- Oxton Alarm and CCTV Supplies - Wallasey
- Oxygen Electronics - Marlborough
- Oyster Terminals UK Ltd - Coventry
