The company has not yet selected a replacement for Westergren, who is likely to stay on at Pandora until a new chief executive is in place, Recode reported on Sunday. bit.ly/2sc8ciP
Westergren, who co-founded Pandora in 2000, served as its Chief Executive and president from May 2002 to July 2004, before returning to the company as its chief executive last year.
The company could not be immediately reached for comment.
Earlier this month, Sirius XM Holdings Inc said it would invest $480 million in Pandora, giving the satellite radio company better exposure to internet music streaming while providing financial footing to Pandora.
Pandora faces stiff competition from services such as Sweden's Spotify, Apple Inc's Apple Music, Google Play Music and Amazon.com Inc's Amazon Music Unlimited, which dominate the on-demand music service market.
Pandora posted a net loss of $343M in 2016, on annual revenues of $1.39B.
According to SEC documents,, the platform’s total active user count in the 30 days to end of March this year stood at 76.7M. Compared to the previous year, that figure has shrunk by 2.7M people.