HELINSKI, FINLAND: Nokia will unveil its first Windows-based smartphones this quarter, targeting a "clear opportunity" for an alternative to the products of big-hitters Apple and Google, the Finnish firm's chief executive said on Tuesday.

"Our belief is that there is a clear opportunity for an alternative ecosystem," Stephen Elop told the audience at a technology fair in Helsinki, adding that he saw the battle extending to tablet computers and televisions.

The world's largest phone maker by volume, left in the dust by Apple and Google, announced its high-risk new strategy at the start of the year which Elop likened to jumping from a burning oil platform.

The firm ditched its home-grown Symbian software for a deal with Microsoft but there has been a long delay between the announcement and the first of its models using the latter's Windows software for smartphones reaching the market.

Already struggling with falling sales and profits, Nokia has subsequently seen its shares halve on worries it would lose so much market share before the new phones come out that it might never make up lost ground.

Meanwhile Apple is expected to unveil the new version of its iconic iPhone later on Tuesday.

Both Apple and Samsung outstripped Nokia in the smartphone market this year, ending its 15-year reign at the top of that market. Nokia's quarterly phone sales to end-June dropped 20 percent at a time when the market grew 10 percent.

Elop, who took over a year ago, last week unveiled a plan to cut 3,500 jobs in its second major restructuring in six months. The latest redundancies come on top of cost cut plans set out in April, which included laying off 4,000 staff.