Japanese operator Softbank has agreed to acquire 100% of struggling personal handyphone service (PHS) operator Willcom.
The deal will go ahead if the Tokyo district court approves Willcom's rehabilitation plan, Reutersreported.
The acquisition would give Softbank an extra 3.9 million subscribers, taking its total to 27 million and narrowing the gap between closest rival KDDI, with its 32 million subscribers.
Softbank in March agreed to acquire part of Willcom's business under a 41 billion yen ($503.4m) rehabilitation plan. Willcom had entered bankruptcy protection in February.
Under the initial proposal, Softbank and investment firm Advantage Partners were to spin off Willcom's next-gen PHS into a new business. But the plan only involved providing financial assistance for the legacy PHS unit.
But in August, Softbank announced that it had agreed to the Willcom trustee's request to provide direct assistance to the PHS unit as well.
Willcom is unable to compete effectively against incumbent mobile operators Softbank, KDDI and NTT DoCoMo. Its customer base is tiny compared to the overall market size of 116.3 million mobile phone and PHS subscribers as of the end of March. PHS technology saw rapid adoption in the mid-1990s against 2G cellular standards in Japan, but has progressively shrunk since the arrival of 3G.