Skanska UK in partnership with Morrison Utility Services has picked up two of the four English regions in a massive deal worth £1.6bn.
The huge haul of work in the East of England and North London regions with be shared equally between the contractors.
Balfour Beatty’s deal is worth £1.2bn and involves design and installation of modern polyethylene gas distribution mains to replace aging metal pipes in the North West and West Midlands.
Work on the new Gas Distribution Strategic Partnership contracts is scheduled to start 1 April and end 31 March 2021.
Balfour will invest £55m of working capital in the contracts.
Balfour Beatty chief executive, Ian Tyler, said: “National Grid is one of our longest held relationships and we are delighted to continue this partnership.
“The award of these new contracts builds on our ongoing strategic focus in the power market and is an excellent example of partnership with our clients to deliver continuing value as well as ongoing certainty to a core element of the UK’s infrastructure.”