'lead contractor' is correct and can be used in written English.
For example: The lead contractor on the project was responsible for ensuring the deadline was met.
But production of the LM fell behind schedule, and when Apollo 8's LM arrived at Cape Canaveral in June 1968, significant defects were discovered, leading Grumman, the lead contractor for the LM, to predict that the first mission-ready LM would not be ready until at least February 1969.
WorldCom, the previous lead contractor, was fired earlier this month.
BT is the lead contractor, and subcontractors to the £530m deal include Cisco, Nortel and NTL.
In Bagram, the civil affairs team has hired a local commander, Gen. Baba Jan, as the lead contractor on projects.
Raytheon is the lead contractor on a $414 million contract to upgrade more than 600 Tomahawk missiles.
Operators typically rely on two or three main suppliers, and the lead contractor on one project may integrate equipment from others.
According to figures released by the NHS, of the 1,028 systems deployed by the regional lead contractors so far under the programme 827 were carried out by Accenture.
This will be a body blow for the NHS as Accenture has been responsible for deploying more than 80% of the systems installed so far by the four lead contractors under the National Programme for IT.
The loss of Accenture from NPfIT - the world's largest non-military IT project, designed to revolutionise the health service's largely paper-based systems - raises questions about the performance of the other lead contractors, BT, Computer Sciences Corporation and Fujitsu.
A parallel recommendation to introduce rules to make lead contractors responsible for compliance through their web of subcontractors – which would go a long way to making major global construction firms responsible for those at the bottom of the chain – has not led to any progress.
And the facts were, from documents we received from lead contractors, that they slowed down to an unacceptable level at 1,100 users.
