Domestic industrial production fell a seasonally adjusted 1.2 percent in April from the previous month for the first drop in two months, the Ministry of Economy, Trade and Industry said Thursday.
The index of output at mines and factories registered 92.5 against the 2000 base of 100, METI said in a preliminary report.
The ministry left its bearish assessment of the state of industrial production unchanged for the sixth straight month, saying "production is weakening."
Regarding the effects on production of severe acute respiratory syndrome, some of the firms surveyed voiced concern over future investment if the epidemic is prolonged, a METI official said.
But none of the surveyed companies blamed SARS for changes in their industrial activity, while the survey suggested no evident impact from the Iraq war, the official said.
Production of general machinery declined 10.9 percent in April from March, with notable drops in the output of semiconductor manufacturing equipment and printing machinery.
This contrasts with the rises recorded in the previous month, when many companies closed their books.
On the other hand, production of transport equipment, including trucks, rose 2.4 percent on robust exports, while production of fabricated metals, including aluminum cans for beverages, surged 4.5 percent.
The index of industrial shipments rose 1.6 percent to 95.6 for the first rise in three months, while the index of industrial inventories declined 0.2 percent to 90.7, the lowest level recorded since 89.4 was registered in August 1988.
Shipments of transport equipment expanded 8.1 percent, thanks to brisk exports of automobiles to North America.
By contrast, shipments of petroleum and coal products slipped 5 percent, as demand for heating slowed.
METI said it expects industrial production to rise 2.6 percent in May and 1.1 percent in June.
New automobile models are expected to be released in May, while some sectors, including electronic parts and devices, forecast brisk business during these two months.