Microsoft on Wednesday announced a set of deals to more tightly integrate services built by other software makers into its Office suite.

People who store Office on Box or Dropbox, along with two other popular online file storage and sharing services, will now be able to edit those documents at the same time as other users. Previously, that function was only available for Office documents stored on a Microsoft service.

The new links between Office and other software are part of Seattle-based Microsoft's effort to broaden the reach of its products by partnering with other , including competitors. In the past two years, Microsoft has released versions of Office for Apple's iPad, delivered free versions of Office apps for smartphones, and announced a range of deals that connected its software to programs built by other companies .Microsoft, a company known at times for pushing customers to use only its services, adopted this more open stance after mobile- and Web-based applications drew people's attention away from the PC, which is the primary home of Microsoft products.

"This is incredibly symbolic of the broad shift that you're seeing in Microsoft," said Aaron Levie, chief executive of Box. The company is "a much more open and interoperable partner within the cloud ecosystem."

Other new features, which Microsoft outlined in a blog on Wednesday, include enabling users of Office on Apple's iOS to access files stored with other companies from within the app. Meanwhile, Box and Dropbox customers using the latest version of will be able to attach files to emails sent through the service.

"We're moving pretty rapidly toward this future world, which is all about working together," said Levie, who grew up on Mercer Island. "The integration is amazing because from a user experience standpoint, I can be using Microsoft Office on my phone and I can get access to all of my files wherever they are."