Costain is to merge with May Gurney.
Costain earned pre-tax profits of about £26 million on revenues o f£930 million in 2012. May Gurney had revenues of about £700 million in its latest financial year, earning profits of #19.3 million.
Costain's existing shareholders will take 53% of the enlarged company, with May Gurney investors taking 47%.
The deal still needs the backing of both sets of shareholders.
More top news
The former MP turned celebrity ED Balls has received an honorary degree from the University of East Anglia where his father was a lecturer.
Ian Poulter has made a record breaking start to the Open at Royal Birkdale.
Feeling fresher. Generally dry and clear overnight