BY ETHAN SMITH AND ERICA ORDEN

Incoming Sony Corp. Chief Executive Kazuo Hirai will need to tread carefully with the company's movie and music divisions, whose profits are important counterpoints to deep losses elsewhere at the company.

Among the decisions Mr. Hirai will need to make soon: whether he can risk distraction from Sony's core businesses by personally overseeing the U.S.-based entertainment operations, or leave those responsibilities to someone in the U.S. Much of Mr. Hirai's focus will be on Sony's electronics division, which posted a $1.1 billion loss in the quarter through December.

Sony has a history of trying to bridge a gap between executives ...