Japanese stocks extended gains Thursday morning ahead of a Bank of Japan monetary policy decision as a weaker yen helped lift export-linked issues, dpa reported. The benchmark Nikkei 225 Stock Average gained 37.78 points, or 0.43 per cent, to trade at 8,918.94 at the end of the morning session at 11:30 am (0230 GMT). The broader-based Topix index was up 1.68 points, or 0.23 per cent, at 747.32. Exporters rose as the yen fell against major currencies. A weaker yen makes Japanese goods less expensive overseas and improves repatriated revenues. Shares in Ricoh Co jumped 2.32 per cent, Sony Corp rose 1.43 per cent, Panasonic Corp climbed 1.24 per cent, Honda Motor Co put on 0.59 per cent and Toyota Motor Corp was up 0.32 per cent. But investors largely stayed on the sidelines as the central bank was to announce its monetary policy decision later in the day. The government said the nation's core machinery orders rose a seasonally adjusted 5.6 per cent in June from the previous month to 709.7 billion yen (9.04 billion dollars) in reaction to May's sharp fall. The increase - which was below a predicted 11-per-cent rise, according to the business daily Nikkei - followed a 14.8-per-cent fall in May. On currency markets at 11:30 am, the dollar traded at 78.48-52 yen, up from Wednesday's 5 pm quote of 78.35-37 yen. The euro was quoted at 97.15-20 yen, up from 96.92-96 yen late Wednesday, and at 1.2377-2380 dollars, up from 1.2370-2372 dollars.