Medtronic, Inc., announced Monday that it will acquire Ardian, Inc., a privately held medical device firm based in Mountain View, California.

Fridley-based Medtronic will make an $800 million cash payment to acquire the company. Medtronic previously held an 11 percent stake in Ardian.

Ardian develops therapies for treating hypertension and other related conditions. Its flagship product, the Symplicity Catheter System, has received European approval and is available in Australia, but has not yet been approved for sale in the United States. The company last week announced positive results from a six-month clinical trial for its device.

“Ardian brings to Medtronic the Symplicity Catheter System and a growing body of evidence to support its clinical use for patients whose hypertension remains uncontrolled despite optimal medical management,” Andrew Cleeland, president and CEO of Ardian, said in a statement. “Our integration into Medtronic creates a tremendous opportunity to leverage Medtronic's global scale and scope to advance the treatment of uncontrolled hypertension.”

The companies expect the transaction-which is subject to customary closing conditions-to be completed during the third quarter of Medtronic's 2011 fiscal year.

Medtronic on Tuesday reported second-quarter revenue of $3.9 billion, up 2 percent from $3.8 billion during the same period a year ago.

Earnings for the quarter that ended October 29 totaled $566 million, or 52 cents per share-a 33 percent drop from the same period last year, when the company reported earnings of $868 million, or 78 cents per share.

The significant decrease in earnings is attributed primarily to a $278 million after-tax litigation charge. In October, the company agreed to pay $278 million to settle a series of lawsuits related to faulty defibrillator wires.

Excluding special items, Medtronic said that it earned 82 cents per share, slightly outperforming the 81 cents anticipated by analysts polled by Thomson Reuters. Medtronic's stock was trading down about 2.6 percent to $33.78 during Tuesday morning trading.

Medtronic is among Minnesota's 10-largest public companies based on revenue from its 2009 fiscal year, which totaled $14.6 billion. The company reported $15.8 billion in revenue for its most recently completed fiscal year, which ended on April 30.