iPhone microchip designer Imagination Technologies showed signs that the worst of its brutal restructuring was behind it on Tuesday as it halved losses, despite slowing demand from its biggest customer.

Shares in the Hertfordshire-based group rose by more than 10pc after a combination of the weaker pound and increasing revenues from its wireless chip designs offset falling demand for graphics units from Apple as sales of the iPhone and iPad fell.

Imagination also announced that Peter Hill, the former chief executive of British technology group Laird, had been appointed as chairman. Mr Hill’s appointment marks a reunion with Imagination’s chief executive Andrew Heath, with the two acquainted from their days at Alent, the chemicals giant.