Japan's telecoms ministry would urge mobile carriers to disclose their leasing fees for mobile virtual network operators, a Reuters report said.
The Reuters report also said the move is part of efforts to increase the number of new entrants to the market and boost competition.
Hefty initial costs of building base stations have deterred many would-be entrants from Japan's cellphone market, dominated by NTT DoCoMo, second-biggest KDDI, and No. 3 Softbank , which bought Vodafone's local unit in 2006.
By asking these and other carriers, including eMobile, Willcom and KDDI-affiliated UQ Communications, to reveal prices and other details of leasing arrangements, the ministry hopes the move will make it easier to negotiate leasing terms and motivate those who want to join the market as virtual operators, the report said.
'Mobile users would be able to see more services offered, and operators would be able to diversify their businesses,' Shogo Matsuda, deputy director at the Ministry of Internal Affairs and Communications, quoted by the Reuters report, said.
'We hope this will boost competition and re-energise the market,' he said.
Nikko Citigroup analyst Hiroshi Yamashina said the move might encourage internet service providers to launch mobile data services, which offer high-speed internet access for mobile devices.
But Yamashina said it would unlikely spur foreign telecom operators to enter Japan, where the number of subscribers has reached 107 million, or about 85% of the country's population.