Tokyo Dome Co., which runs the Tokyo Dome indoor stadium and an adjacent hotel, had for years extended favors to an underworld organization affiliated with the Sumiyoshi-kai syndicate and related companies, it was learned Friday.

These favors included providing tickets to Yomiuri Giants baseball games, as well as discounts on the use of facilities such as Tokyo Dome Hotel, its sauna and the Korakuen Amusement Park next door, sources said.

The favors were allegedly extended to the Otowa clan, based in Bunkyo Ward, and its affiliate firms.

The leader of an underworld group under the Otowa clan was a shareholder in Tokyo Dome Co. and served as the go-between through which tickets changed hands, according to sources familiar with the case.

The firm also allowed individuals with underworld connections to establish temporary stalls outside the dome so they could disperse free horse-racing newspapers. A complex near the stadium contains an off-track betting center.

Tokyo Dome President Yuko Hayashi acknowledged during a news conference that these favors had been extended.

"We have a long history as a public entertainment company, and we could not fully remove the activities of scalpers and other parties (linked with the underworld) in the area around the Tokyo Dome," he said.

But Hayashi denied allegations by the media that the baseball tickets had been handed over free of charge.

"We charged money for the tickets. We are still checking to see how many tickets were sold (to the gangsters) and I would like to refrain from giving a concrete figure at this time," he said.

The firm notified the organized crime section of the Metropolitan Police Agency of its previous dealings with the mob. Authorities on Sept. 11 issued a ban on the underworld groups from entering the relevant premises.