Exploration firm Petroceltic has reported revenues of $38m for the six months to the end of June, down from the $96m reported the same time last year due to lower production and falls in gas and oil prices.
Revenues of $29m came from its operations in Egypt while $9m came from its Bulgarian operations.
The loss for the six month period came to $27m, down from $57m the same time last year mainly due to a much lower exploration write-off.
The company said it had net debt of $184m and its capital expenditure for the six month period came to $29m compared to a figure of $68m for the first six months of last year.
It reported production of 15.7 million barrels of oil a day, which Petroceltic said was in line with its full year guidance.
Petroceltic's chief executive Brian O'Cathain said the firm has remained focused on delivery from its core assets, despite a challenging sector and market environment.
He said the company's Ain Tsila gas development project in Algeria remains on track for first gas in 2018 and continues to be de-risked following the award of the rig contract and the invitation to tender for the engineering, procurement and construction process.
"Maintaining production levels in Egypt and Bulgaria remains a key objective and we are naturally encouraged by Eni’s recent discovery directly adjacent to our offshore acreage in Egypt," he added.