Pandora's stock tumbles after CEO leaves, effective immediately

Pandora Media Inc.'s stock tumbled 8.9% in premarket trade Monday, after the Internet music service said its chief executive officer, Brian McAndrews, is leaving the company after 2 1/2-years in the position, effective immediately. The Internet music service named founder Tim Westergren as its new CEO. "We are pursuing a once-in-a-generation opportunity to create a massive, vibrant music marketplace," Westergren said. "We have the audience, the technology infrastructure, the monetization engine and most importantly the right team with the passion and commitment to do it." The company announced a new management structure, that includes Chief Financial Officer Mike Herring focusing on monetizing the company's core business. Pandora said it expects revenue to come in at the high end of expectations. The stock has plunged 18% year to date through Thursday, while the S&P 500 has slipped 0.4%.

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