Shares in Tullow Oil were down on the FTSE 100 in morning trading, despite the group more than doubling its profits in the half year ended 30 June.

The group reported a rise in sales of 11 per cent to $486 million, while pre-tax profits rose 152 per cent to $131 million in the period.

Tullow Oil said that it would not be raising its interim dividend from last year's figure of 2.0 pence per share.

Production fell in the half year period by six per cent to 55,800 barrels of oil per day, however this was more than offset by the price of oil rising 45 per cent to $77 per barrel. During the period gas prices fell 20 per cent to 34 pence per therm.

In the full year Tullow Oil said it expected production to increase to 57-58,000 barrels of oil per day.

Aidan Heavey, Chief Executive of Tullow Oil, said, "Tullow has continued to make strong progress in the first half of 2010. Our exploration and development programmes are delivering excellent results with significant new oil discoveries being made in both Ghana and Uganda and first oil from Jubilee expected before year-end. With the balance sheet strengthened at the beginning of the year, and the expected proceeds from the Uganda farm-down, we will be very well funded to pursue our exploration-led growth strategy. We look forward with confidence to a promising second half of the year and strong performance overall in 2010."

By 11:20 shares in Tullow Oil were down 5.55 per cent on the FTSE 100 to 1,225.00 pence per share.