Industry body Oil and Gas UK has hailed the latest discovery in the North Sea which could contain as many as 50 million barrels.
Azinor Catalyst said it had struck oil at Agar-Plantain in the Viking Graben area in the Northern North Sea.
Oil and Gas UK said it showed the importance of maintaining strong investment.
Market intelligence manager Ross Dornan said the "sizeable discovery" was "very welcome".
The discovery contains an estimated 15 million to 50 million barrels of recoverable resources.
Oil and Gas UK's Mr Dornan said: "This is further evidence that the improved competitiveness of the industry is encouraging a pick-up in investment.
"Agar-Plantain is a sizeable discovery, in an area with good access to infrastructure.
"This is a further sign of growing confidence in the basin after the increase in applications to the 31st Licensing Round."