Saltfleetby is the largest onshore natural gas field in the UK and has been exploited by Roc since 1999.

The $109m sale of the field to German/Russian-owned Wingas was finalised in December 2004 and helped Roc realise a $72.4m turnaround compared to its $12.9m loss for the previous corresponding period. It includes $13.4m of expensed and written-off exploration expenditure.

The downside to the sale was substantially lower production and sales revenue figures – 38 barrels of oil equivalent per day and $0.4 million compared to 3072boepd and $19 million for the first half of 2004.

"As a result of the strong half-year financial result, Roc was able to self-fund substantial development expenditure at Chinguetti and Cliff Head, as well as a global exploration and appraisal program that will continue well into 2006," Doran said.

Roc has a 3.25% stake in the Chinguetti oil field, offshore Mauritania, and a 37.5% interest in the Cliff Head oil field, offshore Western Australia. It is also operator of Cliff Head.

Chinguetti and Cliff Head remain on track for first oil in 2006.

Exploration activities over the Tiof oil field (Mauritania), the Cabinda South Block (Angola), the Blane oil and Enoch oil and gas fields (North Sea) and Block 22/12 in China’s Beibu Gulf will continue through 2006.