When Google announced its plans in October to revolutionize the software of cellular phones, few were more eager to hear the details than the industry titans at Nokia. They still are.

"We've seen an announcement," Nokia's chief executive, Olli-Pekka Kallasvuo, said with a spoonful of sarcasm. "Conceptually, we could have made that announcement a long time ago."

For a decade, Kallasvuo noted during a recent interview here, Nokia has had its own army of software developers, writing applications for the next generation of mobile telephone services. On the face of it, that is little different from what Google plans to do with Android, an open-source platform for software that aims to transform the mobile phone into a pocket PC.

Of course, Google is - well, Google - just as Apple was not just another cellphone maker when it introduced the iPhone. By virtue of their brains and brawn, and in Apple's case, a cool phone, these interlopers have shaken up an industry long dominated by the quiet giant from Finland.

Nokia's chief said he regarded Apple as the first credible new entrant into this market in years. As for Google, he said he would wait for more details before deciding whether it was a threat or an opportunity. But Google did not invite Nokia to join its Open Handset Alliance, a consortium of 34 companies that includes Motorola, Samsung, and other phone makers.

"It's very clear that Apple, Google, and other players are bringing in a lot of new directions," Kallasvuo said at Nokia's waterfront headquarters in a suburb of Helsinki. "Convergence is a nice, dandy word, but it means industries colliding."

For Nokia, the sudden popularity of the mobile phone business is a double-edged sword. Its core product is emerging as the indispensable device in a wireless, Web-connected world. Nokia has 39 percent of the 1.1 billion-phone global cellular market, more than its next three largest rivals combined. It has half the market for so-called smartphones - Web-enabled devices like the iPhone, Research In Motion's BlackBerry, and Nokia's N95.

But Apple and Google are going after Nokia's franchise on two fronts: Apple as a trendsetter, redefining the look and feel of a cellphone; and Google as an Internet engine, seeking to develop a new software standard for cellphones as they become the principal portal to a mobile Web.

Nokia is also setting out from an uncharacteristically weak position in the United States. It was once a leader there, too, but lost ground after failing to match popular products like Motorola's Razr phone, and its market share, 28 percent five years ago, is now barely 10 percent.

"There's no doubt competition is intensifying," said Carolina Milanesi, a wireless analyst in London for Gartner, the research firm. "Nokia is responding more aggressively than any other vendor to the challenge."

The company, which once made tires and television sets, is plunging into an array of new businesses, like music downloading and navigation, in an effort to pack its phones with multimedia services. Already, its ubiquitous camera phones make it the world's top seller of digital cameras.

In October, Nokia paid $8.1 billion for a digital mapping and navigation software company, Navteq. It wants to use Navteq's maps as the grist for a range of location-based services - enabling users to find a shop or a restaurant in a strange city, for example, or to bring friends together.

"Mobile phones have two qualities that PCs don't have," Kallasvuo said, explaining what has become a credo at Nokia. "They're always with you, and they tell other people where you are."

That might alarm people who cling to old-fashioned notions of privacy. But it is a boon for advertisers who value targeted messages. Privacy is also less of a priority for devoted users of social networking Web sites, like Facebook and MySpace; Nokia views these people as its future.

"More young people are accessing things like Facebook via their mobiles because the sites are often blocked at work," said Mark Selby, Nokia's vice president for multimedia services.

Nokia is also taking on Apple's franchise in music. A new service, Nokia Music Store, allows subscribers to download two million songs on a pay-per-song basis. Next year, the company will offer the 5310 XpressMusic, an ultra-thin phone that holds 3,000 songs and will cost less than $100.

Nokia went even further in a deal announced Tuesday, joining with Universal Music Group to offer a year of unlimited free downloads of songs. It will give subscribers access to Universal's vast catalog, which ranges from Elton John to Amy Winehouse. The songs can be played on either a phone or PC, and subscribers can keep them after the year is finished. Nokia did not say which phones would offer the service, known as "Comes with Music."