Industrial output in May dropped 2 percent on a month-on-month basis, unchanged from the preliminary report, the Ministry of International Trade and Industry said in a report released Wednesday.

The production index for the nation's mines and factories came to a seasonally adjusted 96.3, using 1995 as a base year of 100, marking the fourth consecutive monthly decline.

The shipment index for the reporting month decreased 0.1 percent to 98.2, a downward revision of 0.3 percentage points from the preliminary rise of 0.2 percent.

The inventories index dropped 1.7 percent to 106.7, remaining unchanged from the preliminary figure. However, the inventory ratio index slipped 1.4 percent to 114.4, compared with the 2.2 percent fall listed in the preliminary report.