Shares in Nokia slipped as much as 6 percent yesterday after an analyst firm estimated that the vendor may only manage to sell 500,000 units of its new flagship Windows Phone devices to customers in the current quarter.

In a research note, James Faucette at Pacific Crest Securities downgraded his shipments estimate from 2 million to 1 million, with sales to end-customers estimated at just half a million. "With no breakthrough innovation, we believe Nokia’s new phones are unlikely to get traction in a highly concentrated high end," he said.

Nokia announced the Lumia 800 (pictured) and Lumia 710 last month, its first long-awaited devices running Microsoft’s Windows Phone as part of its transition away from the Symbian OS. Both devices launched on 16 November in selected markets (though not in the US or China) with the Lumia 800 priced at EUR420 and the Lumia 710 at EUR270.

"The market has somewhat elevated expectations for Nokia and its Lumia launch, particularly given the strong backing from carriers that the company is garnering," wrote Faucette. "If Nokia is unable to successfully regain high-end market share in the next several quarters, the stock could return to what we consider a fair value of roughly 4 euros."

According to a Bloomberg report, Nokia was trading around 5.5 percent lower at EUR4.34 by late morning in Helsinki yesterday.

Nokia did not comment on the analyst report and has previously talked up strong early interest in the Lumia devices from both customers and operators. In the UK it said last week that “pre-orders have been higher for Lumia [800] than any previous Nokia handset.”

Nokia is expected to follow up the first two Lumia phones with a raft of other Windows Phones devices in the first half of next year, including – according to reports last week – a tablet running the Windows 8 platform.