The UK arm of Spanish group Pacadar will manufacture the tunnel lining at its factory on the Isle of Grain in Kent.
It will be the largest contract the precast specialist has ever delivered in the UK and will support 180 jobs.
The segments will be used in the first tunnel boring machine drives in London, when two giant machines will be launched in early 2022.
The production will begin in January next year at the factory and the materials will then be delivered to the launch site in West Ruislip by rail where the construction of the twin bored, 5-mile Northolt Tunnel West will begin.
Over 160,000m3 of concrete will be used to make the 7-tonne segments which form a 9.5m outside diameter tunnel 0.35m thick.
Each complete ring is made of seven segments and a key.
James Richardson, managing director of SCS JV, said: “This is an important milestone in the programme as we get closer to launching our first two tunnel boring machines next year.
“We’re building 26 miles of twin bore tunnels, covering the 13 mile distance between West Ruislip and Euston, tunnelling up to 50 metres below ground.
“Using rail to deliver all our segments required for our tunnelling programme will help us to remove one million lorry journeys from the road over the lifecycle of our programme.”
