British chip designer Arm Holdings leapt 11% on renewed speculation that the company could be a takeover target of Apple, one of its clients.
Traders' talk about a possible offer lifted the stock by 31p to 305p by noon, after having reached 362.4p, a jump of 32%, in earlier trading.
The company denied an approach and referred to previous comments by chief executive Warren East, when he said a takeover would make no sense as companies like Apple could already use Arm's technology without buying the business.
The market is speculating that Apple could turn acquisitive given the initial success of the recently launched iPad.
Cambridge-based Arm licenses its technology to a variety of clients, including Apple. The company said in April first-quarter sales rose by 19% to £143.3m, while pre-tax profit soared by 57% to £37.6m.
