Strong sales of medical devices in the United States helped Medtronic overcome international currency headaches and provide a strong ­finish in its final quarter as a U.S.-based company.

Medtronic, which is moving its legal headquarters to Dublin after acquiring Covidien, said net earnings for fiscal third quarter increased 28 percent over the same period last year, to $977 million, or 98 cents per share. Its adjusted earnings per share of $1.01 beat analysts expectations by 4 cents. Revenue increased nearly 4 percent, to $4.32 billion, also topping estimates.

Investors responded by sending Medtronic shares up nearly 4 ­percent, to $78.07.

"Overall, it was just a solid quarter, and very well-balanced across the business," Edward Jones analyst Jeff Windau said. "Their R & D efforts have been paying off, and they're starting to show in their sales."

Even with strong launches of products to improve and monitor patient heart beats, Medtronic's sales showed the signs of an unfavorable currency market.

International sales of Medtronic's medical devices declined by 2 percent to $1.86 billion in the quarter ended Jan. 23, as the dollar's rising value against international currencies erased $158 million in value from sales booked in other countries. Without the currency fluctuations, international sales would have grown 7 percent.

But strong sales in the United States more than made up the difference, with domestic sales of devices jumping 8 percent, to $2.46 billion. Each of Medtronic's three ­existing product divisions reported U.S. sales growth. In particular, ­analysts cheered the 15 percent domestic sales jump in Medtronic's most well-known division, heart and vascular products, which includes everything from pacemakers and defibrillators to artificial heart valves and stents.

Medtronic sold just over $1 ­billion worth of those devices in the United States in the quarter, partly because Americans are returning to more traditional rates of surgeries and interventional procedures following years of relative medical austerity. But all the growth wasn't from the return to traditional demand alone.

"The markets are growing, but not that fast. We've clearly sort of benefited from the strong product launches we've had," Medtronic Chief Executive Omar Ishrak said in an interview. "Has the market improved? Sure it has. We've been through a cycle of instability over the past four or five years, and I really sense that the market is stabilizing."

None of the quarterly figures includes the finances of surgical supplier Covidien, which Medtronic acquired on Jan. 26 for $49.9 billion in cash and stock. Medtronic structured the transaction as a corporate inversion, moving its headquarters to low-tax Ireland as part of the deal. The company's executive offices remain in Fridley.

On Tuesday, Medtronic executives issued guidance saying the company's combined revenue would grow 4 percent to 6 percent in the coming quarter. The company predicted earnings of $1.08 to $1.13 per share for the quarter, despite expectations of losing at least $420 million to currency exchanges.

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