The Apple store has proved the market for software supermarkets in the mobile world, with more than 500 million applications downloaded in only half a year.

Nokia’s market is potentially bigger — it says the Ovi store will reach some 50 million consumers when it opens, while Apple has so far sold less than 20 million iPhones.

But this does not in itself guarantee Nokia’s success.

While hundreds of millions of people use its phones every day, Nokia has yet to match Apple’s success in getting people to pay for software downloads, despite its smaller rival getting a later start. Nokia has also lagged Apple in introducing popular touch-screen phones.

Nokia says it will give 70 percent of all download revenue to developers, just like Apple, if consumers pay by credit card.

But developers will earn less per transaction if consumers opt to pay through their operators, an option that will initially be available in nine countries.

“Because of geographic coverage, credit cards will probably remain the main payment method,” said Marco Argenti, vice president of media at Nokia. “Its going to be the default payment system across the world. (But) in nine countries … developers can activate operator payments.”

Thus far, in cases where consumers can choose between paying via their operator or using a credit card, more than 80 percent use operator billing, Nokia’s own data from the usage of its N-gage gaming service shows.

“We are looking very actively also at this opportunity,” Kallasvuo said, when asked whether Nokia plans to make laptops.

Industry has rumored about Nokia’s possible plan to enter the PC industry since late last year, but Kallasvuo’s comment was the first official admittance of such plans.

“We don’t have to look even for five years from now to see that what we know as a mobile phone and what we know as a PC are in many ways converging,” Kallasvuo said.

“Today we have hundreds of millions of people who are having their first Internet experience on the phone. This is a good indication,” he said.

Nokia’s comments come a week after No 3 PC brand Acer launched a foray into the phone business with eight mobile phone models, joining leader Hewlett-Packard and No. 4 Lenovo in the high-growth space.While strong profit margins in the smartphone industry attract PC brands, the attraction of the low-margin computer industry is less obvious.

“Nokia maybe nervous about entering a market segment that is already heavily commoditized, but it would be in a position to exploit its enormous scale in manufacturing, supply chain and distribution,” said Ben Wood, research director at CCS Insight.

“All leading mobile network operators and retailers are adding connected notebooks and netbooks to their portfolios alongside mobile phones. On this basis it comes as no surprise that Nokia is evaluating this segment,” he said.

The global PC industry was resilient for most of last year when other technology sectors were ailing, but it too has now been caught up in the deepening economic downturn that has hit demand from consumers and corporate buyers.

The Skype experience will be part of the address book of the Nokia N97, enabling presence – seeing when Skype contacts are online – as well as instant messaging. Nokia N97 owners around the world will also be able to use 3G and WLAN to easily make and receive free Skype-to-Skype voice calls, in addition to low-cost Skype calls to landlines and mobile devices.“Making Skype available everywhere through mobile devices is essential to fulfilling our vision of ‘enabling the world’s conversations’,” said Scott Durchslag, Skype’s Chief Operating Officer. “Collaborating closely with Nokia to preload and integrate our software onto their devices will benefit the many Nokia customers who already use Skype, as it makes Skype easily accessible and simple to use on the go. It will also bring Skype new users who love Nokia’s Symbian S60 experience.”

“With more than 400 million Skype users worldwide, the integration of Skype on Nokia Nseries mobile computers is a significant step in bringing converged Internet experiences from the desktop to the world’s most advanced mobile computer,” said Jose-Luis Martinez, Vice President, Nokia Nseries.

The focus of the cellphone market has been shifting to software development since Google and Apple entered the mobile market during the past two years.

The market for software platforms on cellphones is led by the Symbian operating system but it has lost ground over the last year to Apple, Research in Motion and other newcomers.

Nokia , the world’s No.1 cellphone maker, last year bought out other shareholders of UK-based smartphone software maker Symbian and has pledged to make its software royalty-free to other phone makers in response to new rivals.

Since then, 78 companies have said they plan to join the Symbian Foundation to get access to its software.

Atelier, Bank of America , Gemalto, Imagination Technologies, Mobica, Nanoradio, Omron Software, SanDisk , SESCA, SiRF Technology and VirtualLogix said on Thursday they would join the foundation.

In December Google’s Android camp announced new members, increasing its membership to 47.

Nokia will contribute Symbian’s assets to the not-for-profit Symbian Foundation, uniting with leading handset makers, network operators and communications chipmakers to create an open-source platform.

Nokia has said it sees the Symbian Foundation as a faster way to bring new products to market. Foundation members also avoid having to pay fees to outside software developers.

Nokia expects to release the first Symbian Foundation software this year and introduce a new platform by June 2010.