The source said state-owned Qatar Petroleum (QP) will keep the remaining 70% in the new joint venture for the Al Shaheen field, which is 80 kilometres (50 miles) off Qatar's coast and currently produces around 300,000 barrels per day.
Six international oil firms including BP and Shell have bid to operate the oilfield.
For years it was expected that Denmark's AP Moller-Maersk would renew its 25-year production agreement on Al Shaheen field when its licence runs out in 2017.
But
