Shares of Pandora Media Inc. rose the most in two months after the Internet radio service said its audience expanded in each of the top 10 U.S. radio markets.

Pandora’s shares rose 6.5 percent to $10.57 at the close of trading Tuesday in New York, the biggest gain since Oct. 6. The average number of people listening to Pandora for at least five minutes during the average quarter hour rose between 13 percent and 25 percent from September in the 10 cities with the biggest radio audiences, the company said in a statement Tuesday.

“The audience is going up, which suggests that this is a service that consumers like,” John Tinker, New York-based senior media analyst at Maxim Group LLC, said in a telephone interview. “The numbers that came out today are beginning to quantify just how many consumers they actually have in the key markets.”

In November the weekly number of Pandora’s unique listeners exceeded 1 million people for the first time in the New York and Los Angeles metropolitan areas, according to the statement. The company posted its biggest gain in the New York area, where listenership rose 25 percent, the company said.

The Oakland, California-based company has faced growing competition from Spotify Ltd., the music-streaming company that began offering U.S. service in July. Pandora’s shares have slid 34 percent from the company’s June 14 public offering price of $16.