Antrim Energy plunged on Thursday morning after announcing its 30 per cent-owned Cyclone well in the North Sea had failed to strike oil.

The firm said that after drilling 6,076ft it hit 105ft of Palaeocene Cromarty sands but the well logs identified only residual oil.

This suggested that the trap, which was identified as the critical risk factor, was breached, Antrim said.

"Work will continue on the licence to evaluate the remaining prospectivity in light of the Cyclone well result," it added.

The news caused shares to drop 19% immediately after the markets opened.

Its partner Premier Oil, which owns the remaining 70% of Cyclone, said in a separate announcement that the well would be plugged and abandoned.

The much larger firm only saw its shares dip 1.2%.

"While we are disappointed with the Cyclone result, the company has made significant progress on its other North Sea properties," said Antrim's Chief Executive, Stephen Greer.

This included starting production from the Causeway Field and the anticipated start of production from the successful Cormorant East well before the end of the month, the firm said.

The company has also secured an export route for oil from the 11.7m barrel 100%-owned Fyne Field by contracting the lease the "Hummingbird Spirit" Floating Production, Storage and Offloading vessel.

Related share prices
Premier Oil (PMO) share price
Antrim Energy Inc. (AEY) share price