Nokia's wisdom in picking outsider Stephen Elop to return it to its former glory will be tested on Friday when the new chief executive reveals his plans to transform the world's biggest cellphone maker.

Following a leaked memo in which Elop candidly described the need to leap from Nokia's burning platform, speculation has intensified that he will announce a radical switch to use software from rivals Microsoft or Google.

Nokia has rapidly lost share in the higher-margin smartphone market to the likes of Apple's iPhone, and products based on Google's Android platform claimed the top spot from the company last quarter.

In a bid to stem the losses, Chairman Jorma Ollila brought in Elop from Microsoft last September. The 47-year-old is the first non-Finn to head the company.

Nokia's MeeGo platform, its would-be answer to the high-end competition, is as yet unproven, and its workhorse Symbian software has little appeal among developers.

Sources have told Reuters the company has ditched its first MeeGo smartphone project, and Elop himself said in the memo the company might get only one MeeGo device to the market this year.

After Elop raised the possibility of a change in smartphone software, many market followers expect Nokia to adopt either Google's Android or go for Microsoft's Windows Phone 7.

However, picking Android would cede some control to key rival Google, while success in the wireless industry has so far eluded Microsoft.

The Wall Street Journal reported on Thursday that Microsoft and Nokia were in talks about Windows Phone 7. Microsoft and Nokia declined to comment.

Elop is also set to unveil longer-term forecasts, after limiting financial forecasts on January 27 to the first quarter.

He could also unveil a major management shake-up, with some reports suggesting four top managers would be sacked.

(Additional reporting by Jussi Rosendahl in Helsinki and Bill Rigby in Seattle; Editing by Will Waterman, Bernard Orr)