Weak quarterly sales of Nokia smartphones raised the heat on chief executive Stephen Elop, whose decision to adopt Microsoft's untested Windows Phone software has yet to deliver the recovery in the company's fortunes he was hired to achieve.

Nokia has pinned its hopes on its Lumia smartphones to close the yawning lead of the market frontrunners Samsung and Apple, but progress has disappointed many investors and analysts.

Nokia shares fell as much as 6 per cent yesterday after the company said it shipped 7.4 million Lumia phones in the second quarter, up 32 per cent from the first quarter but fewer than the 8.1 million units forecast in a poll of analysts.

Analysts said they were worried Nokia’s Windows Phone models had come too late to the race. – (Reuters)