Pandora Media Inc. P spiked sharply on a rumor that several large Internet companies have expressed interest in acquiring the company. The music streaming company has seen a shrinking profit margin in recent quarters even as its share price is down nearly 1 percent since January. Pandora is periodically the topic of takeover rumors going back at least to 2012. Along with Google and Amazon, Microsoft MSFT is sometimes mentioned as a suitor. Deal Reporter said Monday that Pandora is "attracting interest" from Amazon Inc. AMZN as well as Google Inc. GOOGL and Yahoo Inc. YHOO. But others suggested the report was planted by institutions seeking to squeeze out short interest, which recently equaled 19.7 million of Pandora's 206.5 million shares outstanding. Pandora traded recently up 3.4 percent at $26.17.