Royal Dutch Shell plc, Europe's largest oil company, is expanding its substantial presence in the North Sea with a $525 million purchase of stakes in oil fields there from Hess Corp.

The companies said Thursday that Shell is buying Hess' interests in the Beryl area fields northeast of Aberdeen, Scotland, and a gas transport system called the Scottish Area Gas

Evacuation System. Shell said that with the acquisition, its production in the Beryl fields can increase from the current 9,000 barrels of oil equivalent per day to 24,000 barrels of oil

equivalent per day. The fields are operated by a separate company, Apache Corp. The Beryl fields can also produce for longer than initially thought, Shell said. Hess, which is based in New