KDDI Corp., Japan's second-biggest mobile-phone operator, said second-quarter profit fell 25 percent because of higher promotion costs and losses in the fixed-line business.

Net income declined to ¥58.9 billion in the three months that ended Sept. 30, from ¥78.7 billion a year earlier, the Tokyo-based carrier said Friday. KDDI maintained its full year profit and sales forecasts.

The carrier, which lagged behind rival NTT DoCoMo Inc. and Softbank Corp. in net user additions for the past six quarters, is raising promotional spending and introducing 20 new handsets starting next month to narrow the gap. KDDI also targets a smaller loss in its fixed-line business, scheduled to turn profitable in the year to March 2011.

Operating profit, or sales minus the cost of goods sold and administrative expenses, fell 21 percent to ¥109.2 billion in the quarter, from ¥138.5 billion a year earlier.

Revenue dropped 0.9 percent to ¥869.4 billion, from ¥876.8 billion, KDDI said.

Sales fell short of the ¥871 billion median of five analyst estimates compiled by Bloomberg. Two of the analysts forecast operating income of ¥105.2 billion and ¥109.9 billion.

The company said it expects to pay a full-year dividend of ¥12,000, up from ¥11,000 last year.