** Shares in Novo Nordisk NOVOb.CO rise 3.2% after a report saying activist hedge fund Parvus Asset Management was building a stake in the Danish drugmaker

** The report said Parvus was building a stake to influence nomination of Novo's next CEO, amid investor concerns that the Danish drugmaker has lost its first-mover advantage in the obesity drug market

** Nordnet analyst Per Hansen notes that momentum in Novo shares has turned after the CEO exit announcement, and says that Parvus might be seeing a buying opportunity more than a governance play

** "It is unlikely the stake is mainly about influencing the next CEO; more likely Parvus sees a mix of cheap valuation and market opportunity," Hansen adds

** Novo told Reuters in an email that it does not "have anything to add"

** Parvus did not immediately respond to a request for comment

** Novo shares, at their highest in nearly three months, are among top gainers on the pan-European STOXX 600 .STOXX

(Reporting by Jesus Calero)

((jesus.calero@thomsonreuters.com))