France’s Total is preparing to sell about a third of its stake in the Laggan Tormore gas field west of Shetland along with other oil and gas assets in the UK’s North Sea that could fetch a total of $1.5 billion, Reuters reported, citing “four banking and industry sources.”

The divestment will include stakes in a number of smaller fields Total acquired as part of the 2017 $4.95 billion deal to buy the oil and gas division of A.P. Moller-Maersk, the report said.

Those fields include Golden Eagle, in which Total has a 32% stake, as well as Dumbarton (30%), Bruce (43%) and Keith (25%).

The Laggan Tormore gas field, in which Total now has 60%, started production in February 2016 and can produce up to 90,000 barrels of oil equivalent per day.

The planned sale is part of a big change in the aging North Sea where large players dispose of older fields with declining production while smaller, more nimble companies believe they can extract value.

Last week, Chevron said it was preparing to sell its fields in the central North Sea.

Royal Dutch Shell and BP have also sold a large number of fields in recent years.