Windows Phone chip platform opening up

The new Windows Phone 7 is seen at the Windows Phone 7 launch press conference in New York, October 11, 2010.

BARCELONA (Reuters) - Microsoft Corp plans to open its mobile platform to other chipset suppliers beyond Qualcomm Inc as takeup of its offering grows, a company official told Reuters.

"Adding support to new hardware ... is absolutely part of our strategy," Greg Sullivan, a senior product manager at Microsoft, told Reuters in an interview on the sidelines of the Mobile World Congress trade show in Barcelona.

Last week Microsoft signed a deal with Nokia Oyj to put Windows Phone software on the Finnish firm's smartphones. The first Nokia Windows phones are expected to reach the market at the earliest late this year.

Several key smartphone makers have unveiled Windows Phone models, but Microsoft controlled only 2 percent of the smartphone market in the last quarter. Nokia had a smartphone market share of around 30 percent.

Qualcomm's smaller rival ST-Ericsson, a venture of STMicroelectronics and Ericsson, told Reuters it was focusing strongly on Microsoft's platform to deliver chips and will be ready when Nokia ramps up production of new Windows phones.

"Now everything has changed. The environment is different," ST-Ericsson Chief Executive Gilles Delfassy said in an interview, adding he does not see Qualcomm's exclusive deal prevailing.

ST-Ericsson will be ready to offer Windows Phone chipsets when Nokia ramps up production of its new range of Microsoft phones, Delfassy said.

Williams Financial Group analyst Cody Acree said being only on Qualcomm would likely stifle the competiveness of Windows phones.

"If you only have a single source there's no pricing competition. If you want the best phones with the best prices you're going to want more than one supplier," Acree said.

ST-Ericsson is a key supplier to Nokia, Sony Ericsson and Samsung Electronics, and Delfassy said more major customers were to be announced later this year.

(Additional reporting by Sinead Carew in New York; Editing by David Holmes)