DDI Corp. President Yusai Okuyama on Thursday called for the complete breakup of the giant telecommunications group Nippon Telegraph and Telephone Corp.

"The NTT group should be completely divided and the holding firm of course should be abolished," Okuyama told a regular press conference.

Okuyama, welcoming growing calls to have the NTT group's structure examined, claimed that efforts to create a level playing field have so far been insufficient. He is pushing for an independent body to be created to regulate the dominating telecom giant to secure a fair and competitive market.

Okuyama's remarks coincide with ongoing negotiations between the United States and Japan over the NTT's interconnection fees, which NTT's two regional calling firms charge other telecom firms for using their local networks.

Some NTT executives have been calling for the complete privatization of the entity, roughly 60 percent of which is owned by the government, or greater freedom for the two regional firms in exchange for greater cuts in the interconnection charges.

Okuyama, however, said that a review of the NTT group's structure should not be linked to the access-charge issue.

"We have heard rumors about revising the NTT law to save NTT East and West (in exchange for access fee cuts)," he said. "But that wouldn't gain understanding . . . it would only draw criticism."

DDI Corp. will merge with international call firm KDD Corp. and cellular operator IDO Corp. in October, creating the nation's second-largest telecom group after NTT.

Okuyama is set to head the new firm, which will be named KDDI.