Pertra was a Norwegian

Norway

Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...

 petroleum company. It is based in Trondheim

Trondheim

Trondheim , historically, Nidaros and Trondhjem, is a city and municipality in Sør-Trøndelag county, Norway. With a population of 173,486, it is the third most populous municipality and city in the country, although the fourth largest metropolitan area. It is the administrative centre of...

 and was created when the oil exporation and production division of Petroleum Geo-Services

Petroleum Geo-Services

Petroleum Geo-Services ASA, an oilfield service company, provides geophysical services worldwide. The company provides various seismic and reservoir services, including acquisition, processing, interpretation, and field evaluation. The floating production unit was demerged in 2006 and listed as a...

 was demerged

Demerger

Demerger is a form of corporate restructuring in which the an entity's business operations are segregated into one or more components. It is the converse of a merger or acquisition....

 in 2001. In 2005 it bought five licences from Talisman Energy

Talisman Energy

Talisman Energy Inc. is one of Canada's largest petroleum SB companies. Based in Calgary, Alberta, Talisman Energy has operations around the globe including: Canada and the United States of America in North America; Colombia and Peru in South America; Algeria in North Africa; United Kingdom,...

, including 5% of the operational Varg field. By 2007 it had acquired seven operatorships and six partnerships on the Norwegian continental shelf

Norwegian continental shelf

The Norwegian continental shelf is the continental shelf over which Norway exercises sovereign rights as defined by the United Nations Convention on the Law of the Sea...

. In 2007 it announced a merger with the Norwegian operating subsidiary of DNO

DNO ASA

DNO International ASA is an independent international upstream oil and gas company. The company has its headquarters in Oslo, Norway and is listed on the Oslo Stock Exchange. DNO operates exploration licenses and producing assets in Yemen, the Kurdistan region of Iraq, Mozambique, Equatorial Guinea...

 forming a new company DNO International.