The Aberdeen-based firm, which has a 30 per cent stake in the field, located in the Moray Firth, said it has taken a £12.9 million hit from Athena, reflecting “the collapse in global oil prices”.
As a result, the Aim-quoted group reported a pre-tax loss of £30.8m for the year to the end of June, compared with a £1m profit the previous year.
The sharp decline in oil prices, from almost $110 a barrel to seven-year lows of less than $50, saw Parkmead’s revenues for the year fall to £18.6m, down from £24.7m last time.
However, executive chairman Tom Cross said the firm had made progress, “despite the challenging low oil price environment”.
Cross said that first gas has now been produced from a new field at Diever West in the Netherlands, which was discovered in September last year, with a well recording an “excellent” flow rate of 29 million cubic feet per day, or about 5,000 barrels of oil equivalent.
He added: “As we move towards 2016, Parkmead maintains its appetite for acquisitions and will also seek to add shareholder value through a dynamic work programme.
“The group has built a strong platform from which to become a key exploration and production player in the North Sea, and we look forward to updating shareholders as we make further progress.”