Finnish phonemaker Nokia is moving closer to the change of OS platform the company had planned early this year as a part of the wider strategy to revive growth.

The company’s US subsidiary chief has revealed that Nokia will be out of the Symbian business in North America, when it launches Windows based phones later this year.

In February this year, Nokia entered into a software partnership with Microsoft to power its phones with the new Windows 7 Phone operating system.

In an interview with AllThingsD, Nokia’s US subsidiary president Chris Weber said that the company needs to market its new phones aggressively in the US to win the global smartphone race.

"When we launch Windows Phones we will essentially be out of the Symbian business, the S40 business, etc., " Weber said.

"It will be Windows Phone and the accessories around that. The reality is if we are not successful with Windows Phone, it doesn’t matter what we do."

Nokia has pinned its hope on the North American market.

"We’ll develop for North America and make the phones globally available and applicable," Weber said.

"In fact, evidence of that is that the first Windows Phones that will ship are being done by our group in San Diego."

The phonemaker which recently lost its number one position to Apple plans to go for the most ambitious marketing push in the US.

"Without getting into numbers, it is significantly larger than anything we have done in the past and the most we will invest in any market worldwide," Weber said. "They are putting their money where their mouth is."

Weber is a former employee of Microsoft like Nokia CEO Stephen Elop.

Nokia will not launch its Meego-based the Nokia N9 in the US, said the report.

However, an earlier statement by Nokia Australia managing director suggests that the company has a different strategy for other countries.

In April this year, Nokia Australia managing director Chris Carr had said that Nokia will continue to support new Symbian phones for two years after release owing to contractual arrangements.

Carr said that the company has invested a "lot of money" in Symbian and that Nokia will produce both Symbian and Windows 7 Phone devices till 2012.

"There’s still a lot of ongoing development with Symbian, the two will co-exist. We’ve invested a lot of money in Symbian," Carr had said.

"It’s not unusual in the industry to have multiple OS strategies."

Nokia has been struggling to maintain its lead in the mobile phone market since 2008. Now it faces intense pressure from the growing number of Android-based phones as well as Apples iPhones.

Earlier this year, Elop had announced many drastic steps to revive the fortunes of the company. Those included outsourcing software development, a software partnership with Microsoft to use its Windows 7 OS, and job cuts.

Many analysts believe Nokia’s in-house Symbian OS was a drawback after its phones started facing competition from Apple and Android-based phones. At the lower end, Nokia started losing its market share to the growing number of Chinese mobile manufacturing companies.

Earlier this year, Elop had said that "the Nokia platform is burning", while announcing reforms. The company says that it is in transition mode ever since.

Nokia is still the world’s largest phonemaker by volume. However, it has fallen behind Apple in the smartphone race, selling 16.7 million smartphones in the second quarter this year, compared with Apple’s 20.3 million iPhones.

In their quarterly financial results, Apple’s sales soared earning the company record revenue, up 82%, while Nokia’s operating profit suffered a loss of €487m.

Elop had said while declaring the results that the challenges the company is facing during its "strategic transformation" manifested in a greater than expected way during the quarter.

Elop added, "However, even within the quarter, I believe our actions to mitigate the impact of these challenges have started to have a positive impact on the underlying health of our business."

"While our Q2 results were clearly disappointing, we are executing well on the initiatives that are most important to our longer term competitiveness," Elop had said.