Sales revenue was $17.6 million, compared with $400,000 in the year-ago period, while earnings before interest, tax, amortisation and exploration expense was $3.1 million, compared with $54.6 million.

Nevertheless Roc had a $22.2 million net loss after tax, which includes $26.6 million of exploration expenses. This loss compares with a $56.3 million profit in 1H 2005, which was boosted by the sale of the Saltfleetby gas field.

"The magnitude of change means that the percentage comparisons between the key financial indices for the period under review and those for the corresponding period last year are largely irrelevant," Roc managing director John Doran said.

Doran said the first half of 2006 saw Roc undergo a major transformation from pure explorer to oil producer with exploration upside.

“The period started with negligible production. By June 30, the company was producing approximately 4350 barrels of oil per day from the Cliff Head oil field, offshore Western Australia and the Chinguetti oil field, offshore Mauritania," he said.

“A day later, the company’s production effectively shot up to about 12,000 barrels of oil per day as a result of the acquisition of a 24.5% operated interest in the Zhao Dong Block, offshore China.”

The Perth-based midcap more than doubled its exploration and appraisal expenditure in the period to $35.8 million, mainly due to seismic surveys in Angola and offshore wells in Australia and China.

Development expenditure also increased more than 100% from $30 million to $66.2 million, mainly related to the Cliff Head and Blane oil fields, the company said.