Industrial output fell a seasonally adjusted 3.3 percent in September from the previous month, revised up from a preliminary 4.0 percent drop after adding data that were not available in the earlier report, the government said Monday.

The reading of the index of production at factories and mines represents the first drop in six months, reflecting the yen's steep appreciation and weakening overseas demand.

An official at the Ministry of Economy, Trade and Industry attributed the upward revision to firm output of pharmaceutical products and liquor, for which data were not available when the preliminary report was published on Oct. 28.