The Bank of Japan said Tuesday that its pretax profit for the first half of fiscal 1997 rose 79 billion yen from the previous six months to 1.05 trillion yen, mainly because of the weaker yen.

The profit was the highest since the corresponding period of fiscal 1992, when it came to 1.35 trillion yen. For the period from April to September of 1997, the weakening yen against the dollar brought in 160 billion yen, up 75 billion yen from the previous period.

Another contributing factor to the higher profit was the bank's increased balance of government bonds, from which it earns interest, the BOJ said.