Trading house Sumitomo Corp. said it will begin a tender offer March 3 for shares of Jupiter Telecommunications Co. to become the largest shareholder in Japan's biggest cable television operator.

Sumitomo's move is being seen as an attempt to counter KDDI Corp.'s effort to acquire a major stake in the cable TV firm known as J:Com.

Sumitomo said Monday it will purchase up to 875,834 J:Com shares for ¥139,500 each in the tender offer through April 14.