Royal Dutch Shell is preparing to retreat from high-cost oil operations in the North Sea after 45 years as it attunes its global operations to the new reality of low oil prices.

The company has already cut hundreds of jobs from its UK workforce. In the clearest sign yet that Britain’s biggest company will turn its back on the “super mature” North Sea, Shell told investors its planned $30bn sales drive to tackle its debt burden will focus on mature assets in established oil regions.

Shell’s chief executive, Ben Van Beurden, laid out the company’s strategic plan for the rest of the decade, telling shareholders the group plans to leave between five and 10 mature oil regions, which equity analysts have interpreted as a “heavy hint” that UK assets will be included.