Gloomy analyst comments about the outlook for Motorola, the struggling US-based mobile phone maker, sent the stock tumbling by a further 6.3 per cent on Monday to a new five-year low of $7.44.

Sales of Motorola handsets are dropping at the four major telephone companies in the US, a region that accounts for about half of the company’s handset shipments, said Michael Walkley of Piper Jaffrey, in a note to investors. He estimated that Motorola would probably sell 106m handsets this year, down 8.6 per cent from his previous forecast for 116m.