Heart device maker Guidant Corp. said Monday the Food and Drug Administration has approved the relaunch of an implantable defibrillator that was recalled in June because some had malfunctioned.

Guidant officials said they expect to resume distribution of the Contak Renewal 3 defibrillators by the middle of this week and reach a full product supply by the end of August.

"Our top priority is to provide safe, reliable cardiac rhythm management products and therapies to physicians and patients," said Fred McCoy, president of the company's Cardiac Rhythm Management division.

Implantable defibrillators shock the heart back into a correct rhythm when it beats too quickly. The Contak Renewal 3 was recalled June 24 by Indianapolis-based Guidant after the company discovered they contained a faulty magnetic switch.

The relaunched Contak Renewal 3 line will have a new switch, approved by the FDA. The model is the company's largest seller, analysts have said.

It was one of 11 models the company recalled in June, totaling about 88,000 defibrillators. The company has also issued safety warnings on 28,000 pacemakers.

The FDA approved software to help physicians better manage existing Renewal 3 patients. The company expects the software to be out later this year.

Guidant shares rose $2.84, or 4.1 percent, to $71.64 in morning trading on the New York Stock Exchange, their highest value since June 20.

Guidant shareholders voted in April to accept $76 in cash and stock, totaling $25.4 billion, in a pending acquisition offer by Johnson & Johnson.