Woodside has increased its stake in Blacktip, said to contain 1.1 trillion cubic feet of gas, from 35% to 70%. As part of the deal with Shell, Woodside has also increased its stake in permit WA-313-P from 33.33% to 66.67% and in permit NT-P-57 from 60% to 70%.

Woodside's gas business unit director, David Maxwell, said the acquisition was consistent with the company's strategy to grow the value of existing gas assets and to build sustained growth in the Australian gas business.

"Consolidation of ownership in the Bonaparte Gulf increases our interest in Blacktip and in prospective acreage in the region," Mr Maxwell said.

"Along with our joint venture participant, Agip Australia BV, we are pursuing gas markets in the Northern Territory and evaluating development opportunities for Blacktip." Woodside will continue to operate the permits.