Japan Telecom Holdings Co. announced Thursday it has agreed to sell its fixed-line unit to U.S. investment fund Ripplewood Holdings LLC for 261 billion yen.

The announcement by the country's third-largest telecom company, which is two-thirds owned by Vodafone Group PLC of Britain, capped months of speculation over what will become Ripplewood's largest investment in Japan.

The fund has thus far bought the Long-Term Credit Bank (since renamed Shinsei Bank), Seagaia (a gigantic resort in Kyushu) and other distressed businesses.