Vodafone will this week sell its Japanese fixed-line telephone business to US investment fund Ripplewood Holdings for 260bn yen (£1.4bn), reports say.
Vodafone wants to concentrate on mobiles
"We are close to a final agreement," confirmed Japan Telecom spokesman Aston Bridgman, but would not confirm the details of the deal.
Vodafone, the world's largest mobile phone firm, owns about two-thirds of Japan Telecom, which includes the mobile service J-phone and the fixed-line business.
Vodafone has always said it wanted to concentrate on the profitable J-phone unit rather than the landline business.
The deal would set a precedent in Japan, with two foreign firms striking a deal to sell a Japanese operation.
It is also unusual because foreign investment banks are thought to be cooperating with Japanese banks to finance the acquisition.
Ripplewood, which has funding from a group of banks including Citigroup, was the first foreign investor to buy a Japanese bank.
It took over the failed Long Term Credit Bank in March 2000 and relaunched it as Shinsei Bank.
Japanese papers have reported that, on completion of the acquisition, Ripplewood plans to cut costs, streamline data communications and then float shares in the unit.
But analysts say it will have its work cut out, with the popularity of cell phones and the internet seriously undermining the revenues of
Japan's landline operators.