Transport for London (TfL) has awarded a contract to global transportation systems provider Thales to modernize the signalling and train control system on the next four London Underground (LU) lines.

This next major phase of the Underground's modernization will bring faster, more frequent and more reliable journeys to millions of passengers who use the Circle, District, Metropolitan and Hammersmith & City lines.

In advance of that, customers are already seeing improved services on the four lines as TfL completes the introduction of the new air conditioned trains on the entire network by 2016. Further benefits will include a train control system which will increase capacity further starting with the Circle line in 2021, with additional frequent services at peak times. During 2023 the final improvements will be delivered, with a further boost to peak and off-peak frequency on the Metropolitan line.

The value of the contract with Thales for the signalling and control work is $1.2 billion.

The overall budget for the four line modernization project, confirmed as $8.4 billion, includes investment in 191 new modern air-conditioned walk-through trains, built in the UK, and already introduced on the Metropolitan, Circle and Hammersmith & City and District lines.

The investment also includes further improvements to get the most out of the new trains, including new track, lengthened platforms and rebuilt train depots with advanced technology to ensure the highest levels of train reliability.