Medtronic Inc. announced plans Thursday to sell its external defibrillator business in a $487 million cash deal, five years after it first said the unit was in play.

The Fridley-based medical technology giant said Bain Capital, a Boston-based private investment firm, stepped up to purchase Redmond, Wash.-based Physio-Control.

The business, which has about 1,000 employees worldwide, reported $425 million in sales in fiscal 2010. Its main product is the Lifepak line of external defibrillators, compact units that shock patients who go into cardiac arrest and are commonly found in hospitals, municipal buildings, airports and other public areas. "We are pleased that Physio-Control has found another strong partner to prepare the company for the next stage of its growth," Medtronic CEO Omar Ishrak said in a statement.

The Physio-Control business, which Medtronic bought in 1998, has long been dogged with quality issues, and shipments of some products were suspended between January 2007 and February 2010 as a result.

In May 2008, Medtronic signed a consent decree with the Food and Drug Administration to address problems with the quality systems at the unit. Regulators said that the company failed to correct manufacturing problems and properly investigate complaints related to a model of external defibrillator commonly found in hospitals.

Chris Gordon, a managing director at Bain Capital, said Physio-Control "has built an outstanding brand position and loyal customer base." Growth prospects, he said, appear promising.

Bain Capital, whose founders included presidential hopeful Mitt Romney, manages $66 billion in assets. It has a long history of investing in health care companies, including HCA Holdings Inc. and Air Medical Group Holdings Inc.

Analysts said Medtronic has not wavered since 2006 in its desire to spin off Physio-Control.

"We view this news positively, as Medtronic has been trying to unload this lower-margin business for several years but had difficulty doing so due to outstanding FDA issues," said Rick Wise, an analyst with Leerink Swann.

But David Lewis, an analyst with Morgan Stanley, said the sale "should not be seen as a major event." He noted that Physio-Control only makes up 3 percent of Medtronic's annual revenue of $16 billion.

Medtronic shares closed at $33.86, down 40 cents.

Janet Moore • 612-673-7752