A spokesman said among alternative structures and management enhancements, unifying the two boards to which the CEO would report was one solution being looked at.

Calls for changes to Shell’s dual structure, in effect since the companies 1907 merger, intensified after four reserves downgrades in 12 months and the loss of a number of executives, including former chairman Sir Philip Watts.

The decision comes after a widely reported review of the structures and corporate governance of Shell, which is expected to report at its annual general meeting on June 28.