Shares in Petroceltic rose by up to 18 per cent on the London markets yesterday after the company announced a substantial increase in flow in its AT-1 gas well. The company has also discovered a gas column in excess of 100m in the AT-2 well and has brought forward the planned drilling of its AT-3 well based in the Ain Tsila Ridge area of Algeria.

The independent upstream oil and gas exploration and production company, which is headquartered in Dublin, said the news highlighted the potential of the Ordovician reservoirs and of the Ain Tsila Ridge.