The company now expects organic growth for its audio business, which produces headsets used mainly in offices and call centres, at 16 to 19 percent this year versus an earlier forecast of up to 15 percent.

Analysts at Jyske Bank said GN's second quarter results were "surprisingly strong" and expected growth momentum to improve in the second half of the year and into 2019.

GN, which started in 1869 as a telegraph firm, is best known for its hearing aids. It teamed up with Apple in 2014 and last week with Google parent Alphabet to stream audio from mobile devices.

GN's stock has gained 57 percent so far this year and was the second highest gainer on the European Stoxx 600 index on Wednesday. The stock traded 3.8 percent higher at 0728 GMT.

"Two things help us drive growth above the market. One is we are selling more headsets than the market is growing and second is we are selling better and better headsets, causing prices to go up," the head of GN Store Nord's audio business, Rene Svendsen-Tune, said in an interview.

The company raised its sales and profit forecast for its headset business for the second time this year, earlier raising it from around 9 percent to 15 percent.

(Reporting by Emil Gjerding Nielson; Editing by Jacob Gronholt-Pedersen and Edmund Blair)