On May 14, Third Point CEO Daniel Loeb called on Sony in a public letter to partially spin off Sony Entertainment with a share offering that would increase focus on its profitability.
Hirai rebuffed the suggestion, but in a letter he released publicly in August, he said "we recognize that our (profit) margins should be higher."
Third Point has subsequently cut its stake to about 17 million shares for a 1.6 percent stake in Sony as of the end of September, according to S&P Capital IQ. At the time of his letter, Loeb said the company had 64 million shares.
Since Loeb's letter, Sony's U.S.-traded shares are down 10 percent, closing Monday at $18.72.
The review comes after a weak quarter for the studio. In the three months through September, the movie studio lost about $181 million, which it blamed on box office disappointments such as "White House Down." Revenue rose 9 percent to $1.82 billion, primarily driven by the acquisition of a British TV show production company.
Music division profits rose 24 percent in the quarter to $99 million, while revenue was up 16 percent to $1.17 billion thanks to a weaker yen and hit albums like Justin Timberlake's "The 20/20 Experience."