* Opens technology platforms to outside developers
* Says U.S. success key for services
* Eyeing small acquisitions to expedite services rollout
* Shares up 4.4 pct at 9.76 euros at 1250 GMT (Releads, adds details, quotes, updates shares)
By Tarmo Virki, European technology correspondent
STUTTGART, Sept 3 (Reuters) - Nokia Oyj NOK1V.HE said on Thursday it would start to open its software platforms to external developers in a bid to boost the quantity and quality of software for Nokia phones.
“We are putting a relatively big part of our future into the hands of third-party developers because this is the only way we can be relevant to consumers,” Niklas Savander, the head of Nokia’s mobile Internet services unit, said at the annual “Nokia World” event in Stuttgart.
Apple’s success in the wireless industry has been boosted by its extremely popular application store, which has attracted consumers and developers alike.
Nokia has been looking for business opportunities in offering services, like music downloads or games, to cellphone users as the handset market matures, but so far its offerings have had limited traction.
Savander said the firm’s Internet services have to succeed in the key U.S. market, but success would depend on the firm selling more phones there.
“The U.S. is where we must succeed. The success will need to go hand-in-hand with our devices,” he said.
Nokia controls less than 10 percent of the U.S. phone market, while its global market share is close to 40 percent.
Nokia has also struggled in the U.S. with its services offering — it has delayed the launch of its music service, and a function to enable mobile operators to bill customers for application store purchases was delayed.
Marco Argenti, the head of Nokia’s media business, said in a speech that operator billing with AT&T would be available in the United States in late November.
Savander said Nokia continued to look at buying small technology firms to improve its offering of Internet services, focusing on companies with talented teams developing services that Nokia itself plans to offer in the future, enabling the Finnish company to roll those services out faster.
“It is likely we will find small technology companies,” Savander said.
Nokia bought U.S. digital maps firm Navteq last year for $8.1 billion and has acquired more than 10 smaller firms to jumpstart its Internet services business as growth in the cellphones market is set to stall.
Nokia has revamped the services unit over the last year, selling some non-core businesses, but the company has stuck to two sales channels for mobile games — in addition to its Ovi Store, it sells games through its specialised N-Gage service.
Savander said the success of many application stores was raising the question whether N-Gage was needed, but the answer up until now had been that it was.
Nokia says it has 55 million Internet services users, and the business created April-June revenues of 140 million euros ($200 million).
Nokia shares were up 4.4 percent at 9.76 euros at 1250 GMT, while the DJ Stoxx Tech Index was up 1.6 percent. (Editing by Rupert Winchester/Will Waterman) ($1=.7000 Euro)