Microsoft Corp. is reorganizing into fewer units and promoting executives Julie Larson-Green, Terry Myerson and Tony Bates as the world’s largest software maker works to expand in hardware and Web-based computing.

Chief Executive Officer Steve Ballmer is restructuring divisions around devices and Internet services to address consumers’ growing appetite for smartphones and tablets amid a global personal-computer slump that’s curbing demand for the company’s flagship Windows operating system. He’s also separating corporate tasks like marketing and finance from engineering to help executives focus on building products.

Under the changes, Windows chief Larson-Green will shift to oversee all hardware including Xbox and the Surface tablet, while Windows Phone software head Myerson will lead development of Windows and Windows Phone, the company said today in a statement. Skype president Bates will run a new group for acquisitions and business development and cultivate relationships with software developers and computer makers.

Qi Lu, chief of the online group, will run a unit made up of the Bing search service, Office and Skype. Satya Nadella, current head of the server business, will direct cloud and enterprise products.

Tami Reller, who now leads Windows marketing, will oversee a marketing unit. The finance heads for each division will report to Amy Hood, Microsoft’s chief financial officer. Previously the CFOs in each unit reported to the head of their respective businesses.

Kurt DelBene, who ran the Office division, is retiring.

The shuffle reverses some changes Ballmer made in 2002 when he divided Microsoft into what was then seven individual product units, each led by an executive with operational and financial responsibilities.

Market research firms IDC and Gartner Inc. said yesterday that PC shipments slumped around 11 percent in the second quarter, the fifth straight quarter that PC shipments have dropped.

Xbox head Don Mattrick had been a contender for the hardware post before left the company to become CEO of Zynga Inc., a move announced July 1.