Medtronic Inc. posted a surprising decline in quarterly sales and cut its forecast due to weak demand for its medical devices and pressure on prices, sending its shares down nearly 12 percent to a 15-month low.

The world’s No. 1 stand-alone medical device maker, a bellwether, reported quarterly profit in line with expectations, but weak sales and outlook weighed on the shares of rivals such as cardiovascular device companies Boston Scientific Corp. and St. Jude Medical and orthopedic device makers Stryker Corp. and Zimmer Holdings. Get the full story »