"A gross oil column in excess of 40 metres has been proven" at the Luno II well, the company said in a statement, adding that the oil was of good quality.
The Swedish company said it would provide a range of reserve estimates within two or three weeks.
The discovery was made near Lundin's Edvard Grieg field, as well as the Johan Sverdrup field that two years ago became one of the five largest discoveries on the Norwegian Continental Shelf, and the country's largest find since the mid-eighties.
Johan Sverdrup holds between 1.7 and 3.3 billion barrels of oil equivalent (boe), according to estimates due to be updated in the near future.
"The pressure data indicates that the petroleum system in Luno II is different to that seen in the Edvard Grieg and Johan Sverdrup fields," the company said.
Lundin has a 40 percent stake in the Luno II well, with Norway's Statoil and Britain's Premier Oil holding 30 percent each.