(Adds wage data)
By Tetsushi Kajimoto
TOKYO, Aug 31 (Reuters) - Japan's industrial output grew for the fifth month in July as global stimulus spending boosted exports but analysts warned demand could soon fade and once again put pressure on the world's second biggest economy.
A survey of purchasing managers showed that the manufacturing industry was at its most active in nearly three years this month, although growth in new export orders slowed.
"Japan is picking up from a very low level and we don't want to make the mistake of thinking it is back on a fast track to growth," said Sebastien Barbe, an economist at Calyon in Hong Kong.
"Exports across Asia are still quite weak and we need to see the U.S. economy in particular accelerate."
Factory output rose 1.9 percent in July, beating the median forecast in a Reuters poll of 1.4 percent, but slowing from a 2.3 percent gain in June.
Manufacturers surveyed by the Ministry of Economy, Trade and Industry said they expected output to rise 2.4 percent in August and 3.2 percent in September.
STIMULUS FADING?
Analysts remained cautious, however, noting that the rise in July reflected demand for cars as a result of stimulus spending by governments and that the effect would peter out next year.
"Current output growth is led by one-off factors and the capacity utilisation rate remains low, so a slowdown is anticipated towards the end of this year and early next year and the downtrend may be exacerbated by weak domestic demand in the face of the worsening job situation." said Hiroshi Shiraishi, economist at BNP Paribas.
Japanese wage earners' total cash earnings dropped 4.8 percent in July from a year earlier, after falling a record 7 percent in June, government data showed.
With the jobless rate jumping to a post-war high of 5.7 percent in July and companies under pressure to cut costs to stay competitive, downward pressure on wages is expected to continue. This could add to the deflationary pressures in the economy.
The Nomura/JMMA Japan Manufacturing Purchasing Managers Index (PMI) rose to a seasonally adjusted 53.6 in August, the highest since November 2006, from 50.4 in July.
The index remained above the 50 threshold that separates contraction from expansion for the second month.
The index for new export orders rose to a seasonally adjusted 53.2 in August from 52.7 in July, also the seventh month of improvement, thanks to stronger demand from China. But the pace of the rise slowed to 0.5 point from 1.5 points in July.
"Exports may be losing momentum," said Minoru Nogimori, an economist at Nomura. "We will have to focus on new export orders increasingly as one of the most important indicators regarding the outlook for Japan's economy."
The survey also showed manufacturers continued to expect out put prices to fall, hightighting weak demand.
Industrial output grew 8.3 percent in April-June after falling a record 22.1 percent in the previous quarter, helping the economy return to growth in the second quarter following the deepest and longest recession since World War Two. (Additional reporting by Rie Ishiguro; Writing by Kazunori Takada; Editing by Jan Dahinten)