Japanese industrial output rose for the fourth month in a row in June and is expected to keep climbing as manufacturers restart production lines halted during the country's sharpest post-war slump.

Preliminary data released by the Ministry of Economy, Trade and Industry on Thursday showed June industrial production was up 2.4 per cent month-on-month, a rate of increase lower than the revised 5.7 per cent growth recorded for May but broadly in line with economists' expectations.

The continued rise in output supports expectations that the worst of the current slump in the world's second-largest economy is now over, although it is still unclear how sustained or robust Japan's recovery is likely to prove. Despite the growth since February, industrial production in June was still down 23 per cent compared with the same month of 2008.