The shares, which represent around 15% of the issued share capital, were placed at 91p each and ASCG raised approximately £37.9m in gross proceeds.

The placing was upsized by around 39% from an original 30m shares "on the back of strong deal momentum".

Costain is not party to the placing and will not receive any proceeds.

At 0910 BST, the shares were down 6.1% at 98.60p.