Oil and gas group Santos will gain control of the Darwin LNG plant after buying a range of northern Australian assets for $2.2 billion from United States giant ConocoPhillips, as chief executive Kevin Gallagher shifts further into growth mode three years after rescuing the company.

ConocoPhillips becomes the second big US player to sell down assets in the volatile Australian gas market, after ExxonMobil said last month it would seek a buyer for all its Bass Strait oil and gas operations in a move that could trigger a multibillion-dollar shake-up of the east coast industry.