Demand for studies from North Sea operators was not enough to stop profits plunging at UK infrastructure firm Costain in the first half.

Berkshire-headquartered Costain said its Aberdeen engineering centre was conducting a “significant number of studies” for Premier Oil, Ithaca and Taqa.

But the London-listed firm was impacted by delays to start dates on a number of contracts and the cancellation of a project.

First-half, pre-tax profits slid 57% to £8.4 million at Costain, whose Granite City office is at Carden Place, while revenues sank 21.7% to £594.1m.

However, the company said it was on track to hit its recently revised, full-year targets.

Costain also secured £1.1 billion worth of new contract awards and extensions during the reporting period, swelling its order book to £4.2bn at June 30.

Shares were up 11.28% to £1.61 as of 3:25pm.