Oil and gas explorer Borders and Southern said it made a significant discovery of gas condensate off the coast of the Falkland Islands.
However, the find did not please markets and investors dumped the shares, pushing them down almost 30% in morning trading on Monday.
Analysts said this was because it was a 'technical discovery' and it could be a long time before the find was commercialised.
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The firm said that the main reservoir interval at Darwin East was found to be 84.5m thick with net pay of 67.8m.
Fluid samples from the reservoir have been recovered and will be brought back to the UK for analysis, the firm said.
Once the lab analysis was complete and the results integrated with other data collected from the well, the company said it would be able to comment on the liquid content of the reservoir.
"It is too early to give an accurate resource estimate, but this large simple structure, with a seismic amplitude anomaly measuring 26 square kilometres, is likely to contain significant volumes," the Borders said in a statement.
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