Exploration company Tullow Oil is lining up fresh acquisitions in the North Sea and west Africa after announcing a share issue yesterday to raise almost €15 million.

Tullow believes moves by a number of major petroleum players to offload marginal North Sea interests in a bid to trim overheads, provides a rare opportunity to purchase lucrative oil fields.

The company is also investigating opportunities in west Africa, where it already has substantial interests.

The share issue is expected to raise €14.3 million of which €5 million will be spent servicing debts.

Three years ago Tullow purchased £200 million sterling (€291 million) worth of gas-producing assets in the North Sea from BP which was forced to dispose of the holding to comply with European Commission competition regulations.

Finance director Mr Tom Hickey said the chance to broaden Tullow's North Sea portfolio was "too good to miss".

Tullow also announced that it would swap a 25 per cent stake in one of its North Sea blocks for Shell's 24.8 per cent interest in another exploration well in the region.

The company retains a 50 per cent holding in the Southern Gas Basin Block 53/4a, which contains an undeveloped gas find. The stake acquired by Tullow in the Inner Moray Firth Block 20/7a is held by the Shell subsidiary Enterprise Oil.

Mr Hickey described the move as a straight equity swap.

Tullow said its trading performance last year was satisfactory, with turnover ahead by 47 per cent at £113 million and operating profits before exploration costs up 22 per cent to around £32 million.

It said it had benefited last year from higher oil and British gas prices.