iPhone graphics chipmaker Imagination Technologies put up for sale amid Apple row

British chip designer Imagination Technologies has put itself up for sale weeks after US tech giant Apple said it would phase out the use its products.

The Hertfordshire-based firm said "over the last few weeks it has received interest from a number of parties for a potential acquisition of the whole group."

It added that the board has began a "formal sale process" and has started early talks with potential bidders.

Shares in Imagination plunged by 60% to an eight-year low in April, after Apple said it would design its own graphics chips for future iPhones and iPads, and reduce its reliance on the British company over the next 15 to 24 months.

Royalty payments and licence fees from Apple brought in £60.7m ($77m) in revenues in the year to the end of April, accounting for half of Imagination's total sales. The US giant is also one of its largest shareholders, with an 8.1% stake in the UK company.

The British firm currently has a market value of £350m, but it was worth just under £800m at the start of April.

Last month Imagination launched a formal dispute against the US tech giant.

It is concerned that Apple's plans to replace Imagination's intellectual property – used in the graphics processor units for phones, tablets, iPods and TVs – with its own technology risks violating the company's patents.

It added today (22 June) that it is "remains in dispute with Apple".