NTT Corp. on Monday reported a 30.5 percent drop in group net profit to ¥282.24 billion in the first half of this business year as sluggish earnings at its mobile phone division hurt its bottom line.

In the April-September half, NTT booked an operating profit of ¥646.77 billion, down 13.2 percent, on a 3.2 percent drop in operating revenue to ¥4.998 trillion.

The mobile phone division, however, logged a 16.0 percent drop in operating profit on a 5.4 percent decline in revenue, NTT said.

The long-distance and international telecommunications division saw its operating profit drop 7.6 percent and its revenue fall 3.1 percent.

The local telecommunications service division boosted operating profit by 24.6 percent on reduced operating costs, more than offsetting a 3.5 percent decline in revenue.