By Dana Cimilluca and Cara Lombardo

SoftBank Group Corp. is exploring alternatives including a full or partial sale or public offering of British chip designer Arm Holdings, which the Japanese conglomerate bought four years ago for $32 billion, according to people familiar with the matter.

The review, which Goldman Sachs Group Inc. is advising on, is at an early stage, the people said. It isnt' clear how much interest there would be in Arm from financial or industry players, and it is possible SoftBank will ultimately choose to do nothing.

Write to Dana Cimilluca at dana.cimilluca@wsj.com and Cara Lombardo at cara.lombardo@wsj.com