CAIRN Energy has slashed its workforce numbers by about 40 per cent as the oil and gas firm shifts its focus to West Africa from Greenland.

Edinburgh-based Cairn has axed the jobs of around 90 employees and contractors leaving about 170 people working for the firm.

The company made the cuts under a reorganisation programme announced in August, before it became clear that oil prices were locked in a vicious decline. The price of Brent crude has fallen by more than half since June prompting some firms to make sharp cuts in investment.

As Cairn Energy does not produce any oil and gas the company has been spared the worst effects of the fall.

However, Cairn has seen the value of the company's remaining stake in its former Indian subsidiary plunge from $1.1bn at 30 June to around $700m at 31 December.

The Indian business produces oil and gas from bumper finds made by Cairn Energy under the leadership of its founder Sir Bill Gammell.

Cairn remains embroiled in a tax dispute with the country's authorities, which has prevented the company selling its 10 per cent holding in Cairn India.

Simon Thomson, who succeeded Sir Bill as chief executive in 2011, said: "The company continues to seek a resolution to the Indian tax situation."

Cairn said it is continuing to take all necessary steps to protect shareholders' interests.

Mr Thomson believes Cairn is well placed after achieving significant exploration success off Senegal in West Africa last year.

The company made two potentially significant finds off Senegal.

The successes followed costly reverses off Greenland where the company has spent more than $1bn drilling without making any commercial finds.

Cairn did not mention Greenland in a trading update issued yesterday.

Mr Thomson said the company will focus this year on appraising the discoveries made off Senegal, to see how much oil and gas they may hold, and on trying to make further finds.

He noted that Cairn will benefit from cuts in the rates charged by services companies following the oil price fall.

"The large acreage position in Senegal offers material near term growth potential with numerous follow on prospects identified, and the Joint Venture is well positioned to benefit from the current reduction in industry costs," said Mr Thomson.

Cairn Energy said it expects to complete the sale of a 10 per cent stake in the giant Catcher discovery in the North Sea to Holland's Dyas, for up to $182m, this month.

The sale, agreed in September, looks to have been well-timed given the sharp fall in oil prices since then.

Cairn retains stakes in Catcher and the Kraken heavy oil field off Shetland. It expects both to start production in 2017.

Cairn is currently drilling an exploration well off Morocco. It expects to drill an appraisal well on the Spanish point find off Ireland in the first half of this year.

The company acquired interests in these areas and Senegal under Mr Thomson's plan to combine potentially transformational drilling in under-explored areas with lower risk activity in the North Sea.

Greenland appears to have slipped well down the company's agenda. In the interim results announcement in August Cairn said it remains encouraged by the the opportunity in the Pitu exploration block but that, any further activity on the block will be subject to selling more stakes in its interests. The company said it wanted to minimise capital spending on things like wells in high risk frontier positions.

It has said no more about Greenland since.

The company announced the reorganisation programme with the interim results. It said the reform would ensure staffing levels were appropriate for the future work programme.

It is understood the vast majority of redundancies were completed on a voluntary basis.

Shares in Cairn Energy closed up 4.1p at 164.7p.