Sony Corp.'s So-net and Nippon Telegraph and Telephone Corp.'s OCN Internet service providers are considering joining a proposed Web phone regime under which subscribers to Internet Protocol phone services would be able to communicate with each other without charge, officials of the two firms said Friday.

The creation of the regime has been under discussion among Internet service providers, including Biglobe, an arm of NEC Corp., and Dion, an arm of KDDI Corp. Nifty Corp., a subsidiary of Fujitsu Ltd., also envisions joining the regime.

The participation of So-net and OCN would lead to the establishment of a grand alliance of major Internet service providers offering IP phone services, thus helping bolster the number of IP phone subscribers, the officials said.

The proposed alliance of Internet service providers affiliated with electronics and telecom giants appears to be aimed at fending off competition from the Softbank group, which has been highly successful in wooing new subscribers to its high-speed Net hookup services, due partly to its own IP phone service.