Japan Telecom Co. reported an unconsolidated pretax profit of 13.3 billion yen for the first half of fiscal 1999, compared with 2.2 billion yen for the same period last year, company officials said Thursday.

During the April-September period, the firm's operating profit was 14.9 billion yen, compared with 3.2 billion yen a year earlier, and net profit rose 78.3 percent from the same period last year to 3 billion yen. Sales came to 190 billion yen, up 0.1 percent from the previous year.

The company attributed the increase to growth in the data transmission businesses and reduced operating costs, company officials said.