MANSELL is tipped to take a five-year deal to carry out all Oxfordshire County Council's new build works.
The firm is understood to have seen off challenges from Ballast and Osborne for the job, which has been broken down into two parts - projects valued between £250,000 and £1 million, and projects worth more than £1 million.
The contract is believed to be worth £48 million over five years but can be extended by as much as a further three years.
Local firms Kingerlee and HN Edwards dropped out of contention for the deal earlier this year.
A council spokeswoman said no further details could be released about the contract until the winning contractor had been formally announced.