Japan Telecom Holdings Co., a subsidiary of Britain's Vodafone Group PLC, said Tuesday it swung back to the black in the year through March 31, thanks in part to brisk revenues from its mobile-phone business.

Japan's third-largest telecommunications company posted a group net profit of 79.5 billion yen, against a net loss of 65.97 billion yen the previous year.

"We performed well in the marketplace despite less-than-favorable economic conditions," said Japan Telecom Holdings President William Morrow, adding the group's cost-cutting efforts contributed to the good result.

Group operating profit more than tripled from the previous year to 275.61 billion yen, while pretax profit surged roughly fourfold to 271.87 billion yen.

Sales rose 5.5 percent to 1.8 trillion yen mainly because of the thriving operations of mobile phone unit J-Phone Co., company officials said.

J-Phone's sales rose 8.1 percent to 1.46 trillion yen as its mobile phone subscriptions increased 14.2 percent to 13.96 million.

By contrast, the revenue of Japan Telecom Co., which offers fixed-line telephone services, fell 2.2 percent to 340.1 billion yen. Sales from voice transmission services dropped 11.5 percent to 182.5 billion yen, although revenues from its data transmission business rose 25.6 percent to 87.4 billion yen.

Overall, Japan Telecom posted a net profit of 15.7 billion yen, compared with a net loss of 77 billion yen the previous year.

Japan Telecom Holdings, owned 66.7 percent by Vodafone, is currently in talks with U.S. investment fund Ripplewood Holdings LLC to sell the fixed-line telephone business so it can concentrate on its mobile phone business.

Morrow said his firm and Ripplewood are in the final phase of negotiations but have not yet reached an agreement.

J-Phone meanwhile announced Tuesday it will begin using Vodafone's corporate logo and design on its products and shops Oct. 1.