Shell Plc and Exxon Mobil Corp. have launched a simultaneous sale process of a large package of offshore natural gas assets in the southern U.K and Dutch North Sea, three industry and banking sources said.

Investment bank Jefferies was hired to run the sale, which could raise over $2 billion, the sources said.

Launched earlier this month, the sale comes after Shell and Exxon Mobil ran initial sales processes for their British and Dutch assets.

Shell, Exxon Mobil and Jefferies declined to comment.

In July, Shell and Exxon launched the sale of their 50:50 NAM joint venture in the Netherlands, operator of the Groningen gas field and one of Europe’s largest and oldest natural gas production companies.

Reuters reported that Shell was preparing to launch the sale in February.

Shell and Exxon Mobil are also trying to sell their stakes in their British southern North Sea gas hub, which include the Clipper Leman Alpha hubs as well as the Bacton terminal in eastern England, the sources said.

NAM has launched the sale of the NAM offshore assets independently, one of the people said. The sale of the Southern North Sea and the offshore NAM assets are separate sale processes, allowing for a single or multiple buyers.

The simultaneous sale process of both basins hopes to draw bids from several oil and gas companies that have shown interest in the initial round, the sources said.

The sales are part of the two companies’ drive to dispose of aging oil and gas assets in an effort to cut costs and as they focus on newer, larger projects around the world.