The Rhum field northeast of Aberdeen, which supplies around 5 percent of Britain’s gas demand, has now received a new operation license from the US Treasury, UK-listed producer Serica Energy said on Tuesday.

The license also allows Serica to complete its acquisition of BP’s 50 percent stake in the offshore field, making it a new partner of the Iranian National Oil Company which holds the other 50 percent.

Under the license which is valid until October 31, 2019 but may be renewed, Iran’s proceeds from the field will be held in an escrow account while sanctions are in place.

BP announced in May that it had halted work on Rhum as Serica said it was looking to secure a waiver from renewed US sanctions against Iran.

“Subject to the fulfillment of the conditions, the license will allow certain US and US-owned or controlled entities to provide goods, services and support involving Rhum,” Serica said in a statement on Tuesday.

The US Treasury’s Office of Foreign Assets Control (OFAC) “has also provided an assurance that non-US entities providing goods, services and support involving Rhum will not be exposed to to US secondary sanctions", it said. 

“These OFAC actions will enable production from the Rhum field to continue unaffected,” the company added.

Previous US sanctions between 2012 and 2014 forced the Rhum field to shut down.

Rhum was discovered in 1977 by a joint venture between the Iranian Oil Company UK Ltd and BP which has a long history of operation in Iran.

BP started life as the Anglo-Persian Oil Company in 1908 before parting ways with Iran and becoming British Petroleum. 

The company shut down Rhum in 2010 even before the West began imposing intensified sanctions on Iran a year later. It resumed production in 2014 after securing an exemption.