Skanska will develop, construct and maintain three new PFI schools and extend one existing special school.
The deal kick-starts the first phase of Essex County Council’s £1bn programme to rebuild or refurbish 80 schools throughout the county.
But the programme could run into trouble if the Tories win the election as leader David Cameron intends to scrap the BSF programme.
Skanska will invest £5.1m in return for the £71m build contract and a facilities management deal worth £1.3m each year for 25 years..
Preparatory work has started and the first school will be completed in time for the start of the new academic year in September 2011.
The remaining three new schools are scheduled to open by January 2012.