Microsoft limiting Office app to iPhone

NEW YORK – Even as a pared-down version of Microsoft’s Office software package arrived on the iPhone, the company is holding out on extending that to the iPad and Android devices as it tries to boost sales of its Windows tablet computers.

Microsoft also isn’t selling Office Mobile for iPhone separately. Instead, it comes as part of a $100-a-year Office 365 subscription, which also lets you use Office on up to five Mac and Windows computers. Microsoft made the app available through Apple’s app store Friday.

Microsoft Corp. is treading a fine line as it tries to make its subscription more compelling, without removing an advantage that tablet computers running Microsoft’s Windows system now have: the ability to run popular Office programs.

Microsoft has been pushing subscriptions as a way to get customers to keep paying for a product historically sold in a single purchase. The company touts the ability to run the package on multiple computers and get free updates regularly. Microsoft said it wants to give customers yet another reason to embrace subscriptions by offering Office on the iPhone only with a subscription.

The iPhone app will let people read and edit text documents, spreadsheets and slide presentations at the doctor’s office or at a soccer game. But many people will prefer doing those tasks on a tablet’s larger screen. Office is available on those devices via a Web browser, but that requires a constant Internet connection, which many tablets don’t have.

“The nature of the Office suite, being productivity-focused, makes it better-suited for a larger mobile screen,” Edward Jones analyst Josh Olson said. “The issue then becomes, ‘How do you provide the Office offering in its best-suited mobile environment without negating a distinguishing characteristic of the Windows 8 tablets?’ ”