The firm raised its estimate for the full year through March to a record 740 billion yen from the 380 billion yen it forecast in May.
That came after it said April-September net profit more than quadrupled from the same period a year earlier to a record 360.6 billion yen ($3.2 billion), driven by higher commodity prices such as those of coking coal and iron ore.
($1 = 113.6700 yen)
(Reporting by Yuka Obayashi; Editing by Christopher Cushing)