Rakuten Inc., the largest shareholder of Tokyo Broadcasting System Inc., said Tuesday it has asked the TV broadcaster to buy back its 19.83 percent stake.

The request came a day before TBS becomes a government-certified broadcasting holding company under the revised Broadcast Law, making it impossible for Rakuten to build a planned capital and business alliance.

Rakuten, Japan's largest Internet mall operator, has expanded its stake in TBS since proposing its integration with the broadcaster in October 2005 to combine Internet and TV broadcasting operations.

But its decision to sell the stake puts an end to its long dispute with TBS over the proposal, during which TBS and other broadcasters enhanced their respective online services.

Under the new legal structure to be adopted by TBS effective Wednesday, a single shareholder will not be allowed to acquire voting rights of more than 33 percent in the broadcaster.

Rakuten will hold talks with TBS to set a price for its stake. It will spend the proceeds from the sale on its online shopping and other businesses. TBS stock is quoted at around ¥1,300, well below the average of ¥3,100 per share paid by Rakuten.