The project involves the delivery of a major capital investment programme over three phases covering 12 schools across the borough.
In a trading update Balfour Beatty also announced it was trading in line with expectations and continued to have a strong order book.
In a trading update chairman Steve Marshall said: “Trading performance in 2009 has been in line with expectations, underpinned by our high-quality order book, continued infrastructure expenditure by our customers, the benefit of acquisitions and our tight control of costs.
“We continue to have a strong order book, which, at the half year, is expected to be broadly in line with the £12.8 billion reported for 31 December 2008.
“Our strong market positions, the resilience of our business model and our high-quality order book mean that we anticipate making progress in 2009.”
The company said performance in the building sector had exceeded last year with trading in the UK “steady” and the United States “strong”.