On Thursday, the Santa Clara, California, company will unveil an ambitious $100-million advertising campaign that will span television, radio, national magazines, newspapers and the Internet. Palm plans to showcase the thousands of software applications that can run on a handheld computer - from golfing programmes to blood-measurement applications to a GPS mapping system - all of which rely on Palm's operating system.

Many of the ads, developed by San Francisco agency Citron Haligman Bedecarre, won't even show the Palm machines but instead will display only the device's screen pictured against soaring landscapes and smiling faces. "We're repositioning ourselves as the leading mobile platform provider," says Mr Satjiv Chahil, Palm's chief marketing officer. "If you can dream it, you can do it on a Palm. Our new advertising mission is to communicate this message across all the forms of old media and new media."

During the past few years, Palm has come to be known as the chief provider of hardware of handheld organisers. But in the past 18 months, numerous competitors have jumped into the emerging handheld industry, chipping away at Palm's marketshare for device sales. Earlier this year, for instance, Microsoft unveiled the newest version of its Pocket PC gadgets, which rely on the Redmond, Washington, company's Windows CE operating system. Other companies, such as Handspring and Sony, which have signed agreements to license the Palm operating system, also launched new handheld gadgets this year.

Rivals are skeptical that Palm can position itself as an operating-system company. "The question is, when will Palm develop a real operating system?" says Mr Phil Holden, marketing director of mobile devices for Microsoft who says the Palm platform isn't robust enough to support multimedia and other expanded capabilities. "When you talk about being an operating system company, you've got to produce something that can run on a range of devices, not just on a handheld computer."

In response, Palm executives say they are working on updated versions of the Palm operating system, adding that the platform already is robust enough to support thousands of applications. Although device sales generate about 90 per cent of Palm's revenue, company executives say they expect fee from licensing the Palm operating system to become a heftier proportion of revenue during the next few years.

Palm's new ads, which bear the new tagline of "Simply Amazing" in addition to the old tagline of "Simply Palm," will begin appearing in national newspapers the same day Palm's annual shareholder meeting is held. Each of the new print ads will focus on a different software application. "Most tech brands are to some extent off-putting," says Mr Kirk Citron, chief strategic officer of the ad agency that created the campaign. "But if you show consumers concrete solutions for their daily life, their interest in the mobile Internet increases, and they can see the Palm as a personal companion."

The campaign also will spread to fashion and sports magazines such as Vogue and O, the Oprah Magazine, where Palm hasn't advertised before, says Ms Liz Brooking, Palm's senior director of marketing communications. "We want to go beyond the affluent male demographic to reach a broader audience," she says.Palm also will launch several 30-second and 60-second versions of a new television commercial. The ads will appear on network TV, cable TV and inflight programming. In one spot titled "The Perfect Day," a series of images from daily life flash up to the beat of pulsing music.

At the same time, messages about different Palm applications also appear, such as "Shave three strokes off your golf stroke" (a golfing software programme) and "Carry the office in your pocket" (an e-mail and datebook programme). At the end of the spot, the screen reads, "The perfect day is here." The screen then morphs to say, "With over 10,000 applications, Palm gives you the freedom to do whatever you want, whenever you want." Palm also has bought radio spots of 30 and 60 seconds, says Ms Brooking. There also will be plenty of outdoor-billboard advertising in big cities, including Times Square in New York and Sunset Boulevard in Los Angeles, as well as in Boston, San Francisco and Chicago.

Citron Haligman Bedecarre also has developed a series of new banner ads for Internet advertising. Clicking on the banner ads will connect the viewer to short movies about some Palm software applications. In one banner ad, for instance, clicking on the ad will take the computer user inside a demo of a golf game that runs on the Palm operating system.

The sweeping ad campaign isn't confined to the US and will be seen globally during at least the next year, says Palm's Mr Chahil. "This is a market-making statement," he says. "Longevity is built into this campaign so that we can constantly refresh images and style and keep presenting the newness of the Palm."