Calls by an American billionaire investor for a break-up of Sony could mark the start of the third leg of Japanese Prime Minister Shinzo Abe's radical economic policies: shaking up corporate Japan by removing regulations that have hurt profitability and held back restructuring.

Hedge fund manager Daniel Loeb met Sony executives in Japan this week to personally deliver a letter in which he pressed the Japanese entertainment and electronics giant, famous for the Walkman and PlayStation, to spin off part of its entertainment arm and insurance division.