The two year agreement with LUKOIL Oil Company (LUKOIL) is for West Qurna-2, one of the largest undeveloped oilfields in the world.
Engineers from Weir Group, which is based in Glasgow, will deliver mechanical, electrical, maintenance and pipeline services for the related production facilities.
These include the Mishrif Central Processing Plant, which will initially produce 150,000 barrels of oil per day (bod), increasing to 400,000 bod by the end of this year.
It is expected to start operations in the first half of 2014.
Weir chief executive Keith Cochrane said: "This substantial contract demonstrates the importance of Weir's long experience of working in Iraq and our reputation for delivering high-quality engineering services in support of the country's developing oilfield infrastructure.
"It also reflects our global capability, a key strength of our group which allows us to capture opportunities in high-growth markets and be a partner of choice to our worldwide customers."
Weir said it has invested more than eight million US dollars (£4.81 million) in establishing a service centre in Basra.