Marathon Oil Corp. said Monday it sold off its Norwegian subsidiary to its Norwegian counterpart, Det Norske, for $2.7 billion.

"The sale of our Norway assets advances one of our key 2014 priorities and further demonstrates our commitment to rigorous portfolio management to simplify and concentrate our business," Lee Tillman, Marathon Oil's president and chief executive officer, said in a statement Monday.

The deal, retroactive to Jan. 1, brings $2.1 billion in net proceeds to Marathon after adjustments for debt.

Marathon's exploration and production arm under the terms of the deal agreed to sell off a floating production, storage and offloading vessel, 10 license areas on the Norwegian continental shelf and the North Sea and "a number" of other non-operated licenses in the area.

For 2013, net production for Marathon for its Norwegian operations averaged 80,000 barrels of oil equivalent per day.

Det Norske board Chairman Sverre Skogen said in a separate statement the acquisition adds to a growing portfolio of key assets on the Norwegian shelf.

"The strategy and vision of Det norske has always been to create a strong Norwegian exploration and production company," he said.

Norway is one of the top oil and natural gas producers for Europe.