HELSINKI – Nokia said Friday it has hired Stephen Elop, the head of Microsoft’s business unit, as chief executive officer, seeking to reclaim ground lost to Apple that has wiped $61 billion off its market value.

Elop, a 46-year-old Canadian, will take over as president and CEO of the world’s largest mobile-phone maker starting Sept. 21, the Espoo, Finland-based company said. He will replace 30-year Nokia veteran Olli-Pekka Kallasvuo, becoming the first non-Finn to head the company. Kallasvuo will remain on the board of Nokia Siemens Networks.

“We view the appointment of a leading software executive to the CEO role as a positive,” said Jesper Kruger, an investor at ATP, Denmark’s biggest pension fund, with $64 billion in assets including Nokia shares. “Earlier management grossly underestimated the challenges related to moving from a hardware-driven business model to software.”

Elop, who ran Microsoft’s biggest business, said Friday that the two companies may do more work together. Microsoft and Nokia have both struggled with software for smartphones, sidelined by the rise of Apple’s iPhone and handsets based on Google’s Android operating system.

Three years after Apple introduced the iPhone, Nokia is grappling with developing a smartphone with the same mass appeal. It has been forced to cut prices, sacrificing profits to defend its market share.

“My job is to take the organization through a period of disruption and ensure that we are meeting the needs of customers while delivering superior financial results,” Elop said at a press briefing in Espoo.

The CEO search started in late May and the board considered several internal and external candidates before zeroing in on Elop, Chairman Jorma Ollila said.

“It’s particularly Steve’s strong software background and proven track record in change management that will be the most valuable assets,” he said.

A computer engineer by training, Elop joined Microsoft in January 2008. Elop, who has a management degree from McMaster University in Hamilton, Canada, came to Microsoft from Juniper Networks Inc., where he was chief operating officer.

He also brings to Nokia experience as CEO of graphics software maker Macromedia Inc., before that company was bought by Adobe Systems Inc. He previously worked as chief information officer at restaurant chain Boston Chicken Inc. His resume doesn’t show any jobs in the mobile-phone business.

“Nokia’s board has made a safe choice when they should have made a courageous choice,” said Nick Jones, a London-based analyst at Gartner Inc.