The €425m contract covers project management and construction supervision on lines 1, 2, and 3, and accounts for nearly half of the engineering services on the six-line network. Around 1000 staff will be based in Riyadh to carry out the work.

The joint venture will validate studies, oversee and coordinate construction work, accept engineering structures, and approve pre-commissioning tests.

ADA announced the winning bidders on July 28 for the contracts to design and build six lines totalling 176.7km. The first sections of the network are due to open by 2018.