First Great Western Link

In April 2003 the Strategic Rail Authority invited FirstGroup and Go-Ahead to bid for a two-year extension to the Thames franchise that would coincide with the end date of the First Great Western franchise, after which both would become part of the Greater Western franchise. In November 2003 the Strategic Rail Authority awarded the new franchise to First with the services operated by Thames Trains transferring to FGWL on 1 April 2004.

On 12 June 2005 Heathrow Connect was introduced as a joint venture between FGWL and BAA. BAA supplied the Class 360 rolling stock and on-board staff. FGWL received the revenue for journeys between Paddington and Hayes & Harlington, and BAA the revenue for journeys between Hayes & Harlington and Heathrow Airport.

FGWL ran services along the Great Western Main Line from London Paddington to Didcot with services continuing to north to Oxford, Bicester Town, Hereford and Stratford-upon-Avon. It also operated services on the Greenford, Windsor & Eton Central, Marlow, Henley and Bedwyn lines and on the Reading to Basingstoke and North Downs lines.

The Stratford-upon-Avon service was transferred to Chiltern Railways in December 2004 with FGWL ceasing to operate beyond Banbury.

Great Western Main Line (Local services between London Paddington and Didcot Parkway).

Cherwell Valley Line (Didcot Parkway - Oxford)