SAN FRANCISCO/SEATTLE: It may be one of Microsoft Corp’s biggest squandered opportunities.

Tired of waiting for Office to be optimized for their mobile gadgets, a growing contingent of younger companies is turning to cheaper, simpler and touch-friendly apps that can perform word processing and other tasks in the cloud.

Take Artivest Holdings Inc, a New York-based financial services startup that sells alternative investment products. The New York-based company uses an app called Quip, which combines word processing and messaging, to handle all but the most sensitive legal and financial files.

“There are no more Microsoft Word documents being circulated. If someone e-mails me a Word document, I’ll tell them to put it in Quip,” said Artivest Chief Investment Officer David Levine.

“If I’m walking to and from home, or going to an appointment, I can review or edit on my iPad. Not being tied to my desk, that’s a big pro,” he said.

The speed with which apps like Quip have been adopted is forcing Microsoft to intensify its efforts to bring the powerful but aging Office software suite to tablets and smartphones, according to people close to the company.

Microsoft already has a full iPhone and iPad version of Office ready for release, the sources said. The only question is when CEO Satya Nadella, who took over in February, will pull the trigger.

Nadella wants to widen Office’s customer base but has to balance that with the flagship Windows franchise, which benefits greatly from tight integration with Office, especially on desktop computers.

“We have some pretty exciting plans,” said John Case, the top Office marketing executive, without giving any details. “Certainly, interest in Office on the iPad is extreme. When they (customers) want to do real work, they are going to want to use Office.”

Investors for years have urged Microsoft to adapt Office, its most profitable product, for mobile devices from Apple Inc. and Google Inc. — rather than shackling it to Windows as PC sales decline.

Activist investment firm ValueAct Capital, whose president Mason Morfit sits on Microsoft’s board, has more recently voiced misgivings about Office’s continued mobile absence, sources familiar with the firm said.

According to one analyst estimate, Microsoft is giving up $2.5 billion a year in revenue by keeping Office off the iPad, which has now sold almost 200 million units.

“Office is being disenfranchised on the hottest growth platforms,” Nomura analyst Rick Sherlund wrote in a note to clients. “Maybe it is time to focus on Office independent of Windows.”

Some analysts say it may be too late for Microsoft to win back the iPad generation, even if it introduces a mobile-optimized Office suite in the next few months, as expected.

“Look at the applications that are on the rise to support mobile. It is not Microsoft OneNote or Word. It’s Dropbox, or Evernote,” said Ted Schadler, an analyst at tech research firm Forrester. “It’s really about being everywhere. That’s an important, immediate decision that Satya’s going to have to drive.”

Microsoft’s productivity tools remain the industry standard, with more than a billion users spending almost $25 billion on them last fiscal year. But Office revenues are driven primarily by corporate officers who buy for large workforces — and more than half of America’s employees use a mobile device daily to supplement their work.

The rapid rise of apps such as Quip, Haiku Deck, Prezi, Paper, Smartsheet, Good and Evernote, not to mention Google Apps, is nibbling away at the Office franchise. That is particularly true among mid-sized and smaller companies, which tend to be more frugal and less dependent on legacy Office documents or spreadsheets.

Ian Ray, a network administrator at Cypress Grove Chevre Inc, a cheese maker based in Arcata, California, has most of his 35-member workforce using web-friendly apps on iPads and Google Chromebooks.