Britain’s Oil and Gas Authority (OGA) has launched an offshore licensing round for a field in the North Sea that is estimated to hold as much as 300 million barrels of oil equivalent (boe), it said on Jan. 31.

Companies have until May 2 to bid for the Greater Buchan Area, where oil production started in 1981 but where much volume is believed to remain untapped, and which the OGA would like to see exploited by companies partnering up.

“This is a material opportunity. To put this in context, the last discovery made in the U.K. of this scale was Rosebank in 2004,” said Ross Cassidy, senior research manager for the North Sea at Wood Mackenzie.

“The... volumes are a mix of redevelopment, undeveloped and yet-to-find volumes...[It] is surrounded with infrastructure at Golden Eagle, Buzzard, Scott, Forties and Kittiwake, making a tie-back to existing infrastructure possible. A minimum of 75 million boe is likely to be required to be commercially viable.”

The auction starts after Total SA (NYSE: TOT) and partners including China’s CNOOC Ltd. (NYSE: CEO) announced a new gas discovery in the British North Sea’s Glengorm prospect, with recoverable resources estimated at around 250 million boe.

The British North Sea has been undergoing a revival, attracting a new breed of investors in the form of private-equity-backed oil companies and majors rejigging their portfolios in the region.

The OGA plans to auction other mature offshore licenses this summer.