The Posts and Telecommunications Ministry on Monday approved a plan by DDI Corp., KDD Corp. and IDO Corp. to merge under DDI's banner.

After the merger is approved, the new entity will be launched Oct. 1 and will rival telecom giant Nippon Telegraph and Telephone Corp.

DDI is a long-distance carrier belonging to a corporate group headed by electronics maker Kyocera Corp. IDO is a mobile-phone operator affiliated with Toyota Motor Corp., and KDD is Japan's largest international telecom carrier, with Toyota as its major shareholder.

The ministry also OK'd a planned reshuffle of nine J-Phone group companies, which operate mobile-phone services, planned for Oct. 1.

J-Phone Tokyo Co., J-Phone Hokkaido Co. and J-Phone Tohoku Co. will merge, as will J-Phone Kansai Co., J-Phone Hokuriku Co., J-Phone Chugoku Co., J-Phone Shikoku Co. and J-Phone Kyushu Co.

J-Phone Tokai Co. will remain in its current state.