Shares of Six Flags Entertainment (SIX) dropped in afternoon trading after the company announced the retirement of its chief executive officer after just 17 months in the role. Following the news, an analyst said the news that the company's current chairman and former CEO is returning to the CEO role is "a positive."

CEO DEPARTURE: Six Flags announced this morning that CEO John Duffey has retired from the company after less than two years. The theme park operator said it named Jim Reid-Anderson, its executive chairman since February 2016, as its new chairman, president and CEO, effective immediately. Reid-Anderson had served as Six Flags' CEO from August 2010 through February 2016. No explanation was provided by Six Flags for Duffey's departure. Reid-Anderson, who thanked Duffy for his contributions during his tenure with the company, commented that he is "very proud and excited to rejoin the operating team and look forward to executing our business strategy" and that he believes "the best is yet to come." Six Flags is expected to report quarterly earnings on July 26.

ANALYST COMMENTARY: Oppenheimer analyst Ian Zaffino reiterated his Outperform rating on the stock following news that Duffey is leaving and Reid-Anderson is returning, calling it "a positive." Zaffino said in a note to clients that Reid-Anderson was the main driver of the company's strong performance following its bankruptcy, calling him a "management legend."

PRICE ACTION: Shares of Six Flags Entertainment are down nearly 4% in afternoon trading to $56.75.

OTHERS TO WATCH: Other theme park operators include Cedar Fair (FUN) and SeaWorld Entertainment (SEAS), both of which are lower this afternoon.