TOKYO The Japanese Telecommunications Ministry is considering requiring NTT Docomo Inc. and other mobile phone companies to open their networks to newcomers, a newspaper said Sunday.

The Ministry of Public Management, Home Affairs and Posts and Telecommunications may oblige the firms to lease the networks for the brand-new third-generation (3G) mobile service, AFP quoted the**** Nihon Keizai Shimbun***** as saying.

The ministry move follows a decision by KDDI Corp. to become the first Japanese carrier to open its mobile network to other companies, the economic daily said.

KDDI, Japan's number two telecoms firm, has basically agreed with a Tokyo-based Start-Up Company to lease surplus networks for personal handyphone system (PHS) limited mobile services, it said.

Virgin Group of Britain is also approaching KDDI for possible use of its cellphone networks, it said.

No immediate comment was available from KDDI.

If established Japanese mobile phone operators open their networks, it would make it easier for foreign companies and smaller carriers to enter the market even without a government license for wireless services.

It would lead to the introduction of more competition and lower rates, the ****Nihon Keizai**** said.

The ministry plans to set up a study group Friday to consider measures to activate Japan's mobile phone market, it said.

Japan's top mobile firm NTT Docomo started the world's first trial 3G service in Tokyo and two neighboring cities in late May, facilitating rapid transmission of video images and data.

The 3G service is supposed to transmit data up to 40 times faster than the current internet-capable I-mode service. Its introduction of a commercial service in the Tokyo area is planned for October.