£119m funding to spend on upgrading railway lines and stations for the South Wales Metro has been announced.
The EU cash forms part of phase two work on the Merthyr, Treherbert, Aberdare and Rhymney lines.
KeolisAmey won a £5bn bid in May to run rail services in Wales and the new South Wales Metro for 15 years.
First Minister Carwyn Jones said it meant work could start "on the valleys lines to make faster and more efficient journeys a reality".
Phase two of the project is due to be finished by 2023.
Cabinet Secretary for Economy and Infrastructure, Ken Skates, said: "Today's funding will be used to provide faster services, with modern facilities, and provide better connection throughout the valleys."
KeolisAmey has to deliver the long-promised metro - improving public transport links between Cardiff and the south Wales valleys and beyond - as part of the contract awarded by the Welsh Government.
It includes taking more than 124 miles of the valleys lines from Network Rail.
The funding announcement includes:
- £21.1m for doubling track on the Merthyr line, new platforms and an improved interchange at Merthyr Tydfil station
- £27.4m for the Treherbert line and new platforms
- £23.7m to double the track on the Aberdare line, a new platform, new step-free access and waiting rooms at Aberdare, and an improved interchange at Abercynon
- £19.5m for doubling the track on the Rhymney line and new platforms, including step-free access and a new waiting room at Rhymney
- £27.3m for the Taff's Well depot for land purchase, building roads and rail access