Sumitomo Corp. said Thursday it has concluded its tender offer for Jupiter Telecommunications Co., a move that is expected to make the trading house its largest shareholder.

Sumitomo said it spent about ¥122.1 billion, or ¥139,500 per share, from March 3 to Wednesday to build its stake in Japan's leading cable television operator, which is also known as J:Com. Its stake is expected to rise to 40.5 percent from the current 27.7 percent.

Sumitomo, currently the No. 2 shareholder in J:Com, carried out the tender offer to counter a similar effort by KDDI Corp., Japan's second-largest mobile phone carrier. KDDI now has a stake of 31.1 percent.

The trading house said some 2.6 million J:Com shares were offered, far above the 875,834 shares it signaled it was willing to buy.

J:Com, which has successively accepted chief executives from Sumitomo, supported the offer after the trading house agreed to hold talks with KDDI afterward on how to ensure synergistic effects from the three companies' efforts.