HELSINKI - Prices of smartphones using Microsoft's Windows Phone software platform will fall fast, Nokia's chief executive Stephen Elop said on Friday.

Last week Nokia, the world's largest phone maker by volume, said it would adopt Microsoft's software across its smartphones, raising fears the firm would miss out during the transition on surging demand for cheaper smartphone models.

Elop said one of the key topics in the talks on doing a deal with Microsoft was convincing Nokia that it could reach "a very low price point."

"We have become convinced that we can do that very quickly," Chief Executive Stephen Elop said in a meeting with Finnish business journalists.

Trying to better compete with Apple's iPhone, Microsoft has so far had tight hardware requirements for phone models using its software -- pushing up handset prices and limiting the potential market.

As part of the push to a wider market and lower prices, Microsoft plans to open its mobile platform to other chipset suppliers beyond Qualcomm.

Nokia's shares dropped more than 20 percent after it announced the Microsoft deal, but industry executives have said the new alliance will be good for competition and innovation.

Elop said the final agreement between Nokia and Microsoft would be signed in the next few months.

"The conclusion of the agreement will happen, we think, quite quickly, measured in a couple of months, it may be a bit longer, it may be shorter," he said.

ELOP SELLS MICROSOFT, BUYS NOKIA

Elop, who joined Nokia from Microsoft last September said he sold all his Microsoft shares on February 17 and has bought 150,000 shares in Nokia. The Canadian is the first non-Finn to head the firm.