Communications minister Heizo Takenaka declined comment Tuesday when asked whether his ministry will rescind the license granted to Softbank Corp. in November that authorized the company to enter the mobile phone business.

Softbank is currently in talks with Vodafone Group PLC to acquire the British giant's Japanese unit, Vodafone K.K.

"We will deal with the matter in accordance with the radio law after hearing details about Softbank's business plan," Takenaka said, adding he was not position to comment on whether Softbank's license to operate in the 1.7-gigahertz frequency band should be revoked, because details of the proposed buyout have yet to emerge and the deal is still hypothetical.

Vice communications minister Shogo Hayashi said Monday the license was granted on the premise that Softbank entered the mobile business on its own.