Shares in ARM Holdings Plc, the UK-based Risc chip designer, fell back 3.6% yesterday the after rumors that Intel Corp was about to bid for the company failed to turn into reality. ARM shares have risen from 715 pence to a peak of 3,185 pence in the past year amid a flurry of licensing deals. But the buzz that its technology will prove too tempting a bait for Intel continues to excite investors.