The shares of the company that made the touchpad for Apple have slumped after it was revealed that the company is not using Synaptics TrackPad in its newly revamped line of PowerBooks.

Synaptics shares slumped almost 16 per cent on Monday – $6.23 a share – after Bear Stearns analyst Andrew Neff cut his price target on the stock due to concerns about the touchpad-technology company's relationship with Apple.

Neff expressed concern that Apple's decision to stop working with Synaptics "may signal a change in Apple's strategy whereby in the future Apple may source all of its interface solutions internally," according to MarketWatch.

Synaptics also provides the technology for the iPod click wheel, and other products in Apple's range.