Sales at Kokusai Denshin Denwa Co. fell to 144 billion yen on an unconsolidated basis in the first half of fiscal 1998, down 5.8 from the same period last year, the nation's biggest international telecommunications carrier announced Thursday.

In its midterm earnings report for the April-September period, KDD posted a pretax profit of 5.1 billion yen, down 44.9 percent from the previous year. Net profit also dropped 52.4 percent, to 2.2 billion yen, from the year before.

The poor performance was attributed to the stagnant economy in Asia, declines in private consumption and the increase in discount rate services, KDD officials said. "We are having the worst time. We want to reverse (this trend) by expanding our domestic service and multimedia-related service, which is growing rapidly," said KDD President Tadashi Nishimoto.

Although KDD's domestic service, which started in July, contributed 3.8 billion yen in income toward midterm earnings, overall revenue for voice traffic slid 8.7 percent, to 117 billion yen.