Skanska has been selected as the preferred bidder for the £1bn Essex Building Schools for the Future contract.
The Swedish contractor pipped Carillion to the giant contract.
The Essex BSF programme will involve 80 secondary schools in the county being rebuilt or refurbished over 15 years. It is one of the biggest jobs to go through BSF, along with Birmingham and Kent.
The first phase, procured under wave four of the £55bn BSF programme, will involve work on eight schools and is worth about £150 million.
Work on the first schools in the programme - The Cornelius Vermuyden School and Arts College on Canvey Island, Castle View School on Canvey Island, Pioneer School in Basildon, and Columbus School and College in Chelmsford - is due to be completed by January 2012.
Essex County Councillor Stephen Castle said: “We are delighted to be working with Skanska RM on this exciting project. BSF will bring substantial investment to Essex, enabling us to build world-class facilities that will transform education and the way it is delivered.”
Skanska RM development director, education Steve Cooper added: “Everyone at Skanska RM is delighted with this announcement, now the hard work begins and we look forward to a long-term partnership with Essex County Council to deliver the schools for the future.”