Note: This is only a list of passenger operating companies. This is fairly full, I have included a website of each company if one exists.
The Anglia franchise has been let to GB Railways Group plc, a company formed specifically to pursue the opportunities offered by rail privatisation.
The Cardiff Railway Company runs services radiating from the Welsh capital into the Valleys. The franchise of this company was awarded to Prism Rail. It operates 75mph (120km/h) diesel multiple units.
http://www.rail.co.uk/cardiff/home.htm
This company operates trains over the Chiltern Line out of London Marylebone station. The franchise of this company has been let to M40 railways (Management Team). It operates the 75mph (120km/h) DMUs and recently in 1998 it has started operating 100mph (160km/h) DMUs which feature brand new windows that block mobile phone transmissions, after customers complained about mobile phone use. The line runs to Birmingham Snow Hill, although it takes about 2 hours to complete the trip. Most people going from Birmingham to London use Virgin trains or Silverlink Country on the West Coast Main line.
http://www.chilternrailways.co.uk/
This company operates mainly 3rd rail electric trains out of London Waterloo. The franchise has been let to Connex Rail (subsidiary of Compagnie Generale des Eaux). On suburban services around London the name "South London Metro" will be used. The rolling stock wears the name "Connex South Central".
This company operates mainly 3rd rail electric trains in South Eastern England (Kent). The franchise has been let to Connex Rail (subsidiary of Compagnie Generale des Eaux).
Central Trains Limited links the towns and cities of mid
Wales, the Heart of England and East Anglia with a network of
fast, comfortable services as well as providing local services in
the East and West midlands, mid Wales, Lincolnshire and across to
Norwich. The franchise (the last one of all TOCs) was let to
National Express.
http://www.rail.co.uk/central_trains/home.htm
This company operates the Eurostar trains to Paris and future
night trains to/from the continent. London&Continental
Railways won the right to built and operate the Channel Tunnel
Rail Link between London King's Cross and the Channel Tunnel.
Included in the agreement was former EPS and St Pancras station.
London&Continental Railways is a consortium of mainly
building and design companies as well as Virgin.
http://www.eurostar.co.uk
This company operates trains over the Great Eastern Railway out of London Liverpool Street. The franchise has been let to FirstBus plc.
GNER is the new name of BRs InterCity East Coast. This company
operates services between London King's Cross, Leeds, York,
Edinburgh and Glasgow over the East Coast Main Line. The
franchise of this company has been let to Sea Containers Ltd.
http://www.gner.co.uk
Great Western provide InterCity Services between London, South
Wales, the Cotswold and the West of England. They operate out of
London Paddington Station. The Franchise for this company has
been let Great Western Holdings (Management Team and FirstBus).
http://great-western-trains.co.uk/
This company operates the Gatwick Express trains between
London and Gatwick Airport. The franchise for this company has
been let to National Express.
http://www.gatwickexpress.co.uk/
The Heathrow Express service between London Paddington station
and Heathrow Airport is operated by BAA plc, the airport
authority. From June 1997 trains are operated between Paddington
and the entrance of the tunnel under the airport, every 15
minutes.
http://www.heathrowexpress.co.uk/
This company operates train on the Isle of Wight. The franchise for this company has been let to Stagecoach Holdings Ltd.
This company operates trains on the London, Tilbury & Southend line. The franchise has been let to Prism Rail.
This company operated 3rd rail electric trains on Merseyrail around Liverpool. The franchise has been let to MLT Trust Holdings Ltd. MLT already operates buses in both London and Liverpool. November 1996.
Midland Mainline Ltd. operates InterCity trains on a fast and
frequent service between South Yorkshire, the East Midlands and
London St Pancras. The franchise for this company has been let to
National Express.
http://mml.rail.co.uk/
This company operates local trains around Birmingham and
Manchester. The franchise has been awarded to Great Western
Holdings.
http://nwt.rail.co.uk
This company operates local trains around Leeds and York. The
franchise for this company has been let to MLT Trust Holdings
Ltd.
http://www.rrne.co.uk/
ScotRail operates both long-distance trains in Scotland and
commuter trains around Edinburgh and Glasgow. The franchise has
been let to National Express in February 1997.
http://www.scotrail.co.uk
This company - formerly known as North London Railways, operates suburban services north of London (London Euston-Watford, Watford-St. Albans Abbey, North London Line and Gospel Oak-Barking) under the name "Silverling Metro" and regional services (London Euston-Birmingham and Bedford-Bletchley) as "Silverlink County". The franchise for this company has been let to National Express
This company operates mainly 3rd rail electric trains out of
London Waterloo to the Southwest (e.g. Portsmouth). The franchise
was awarded to Stagecoach Holdings Ltd.
http://www.alphaline.co.uk
This company comprises an extensive DMU-operated regional and local network embracing West Wales, south-west England and South Coast destinations such as Portsmouth and Weymouth. They operate under the name Alphaline Rail Service. The franchise of this company has been let to Prism Rail.
This company operates trains through the Thameslink tunnel in London. The franchise has been awarded to GoVia, a joint venture of the British Go-Ahead group and French public transport operator VIA-GTI.
Thames Trains operates the important Thames Valley commuter
trains, as well as longer-distance services to
Stratford-upon-Avon and Hereford, and the important
Reading-Gatwick Airport link. The franchise has been let to
Victory Railway Holdings Limited, a joint venture between the
Go-Ahead Group and Thames Trains management.
http://www.rail.co.uk/thames/home.htm
Virgin West Coast Ltd.Virgin trains operates the former InterCity West Coast and Cross Country. West Coast provides InterCity train services between London Euston and the West Midlands, the North West and North Wales and over the border into Scotland. There are regular weekday services every 30 minutes between London and Birmingham, every hour between London and Manchester, Liverpool and Preston. CrossCountry operate InterCity and Express services from Scotland, the North West and North East through the Midlands to the South and South West - and back again. This is the largest passenger rail company in the UK and have ordered some fast trains for the UK.
The West Anglia Great Northern franchise has been let to Prism
Rail plc.