(Adds breakdown of output, jobs data)
* April output stages rebound from decline in March
* Consumer spending slows in sign of concern
* Tokyo inflation slows slightly in May
* U.S.-China trade war drags on, threatens global economy
By Stanley White
TOKYO, May 31 (Reuters) - Japan's industrial output rebounded in April, though retail sales grew at a slower pace from the previous month, suggesting that both domestic and external demand could come under severe pressure in the event of a protracted Sino-U.S. trade war.
The rise in industrial output was also mainly because Japanese companies front-loaded production before a 10-day public holiday from late April to early May.
Excluding this factor, analysts caution that it is too early to turn optimistic on Japan's factory output as hopes fade for a quick resolution to the trade row between the United States and China, the world's two largest economies.
Industrial production rose 0.6% in April from the previous month, more than the median estimate for a 0.2% increase and following a 0.6% decline in March.
Output was pushed up by an increase in production of cars, airplane parts, and machines used to make flat panel displays, the data showed.
However, in a more worrying sign, inventories of semiconductors and electronic parts rose at the fastest pace in seven months, suggesting weak demand in that sector will also weigh on output in the future.
Manufacturers surveyed by the Ministry of Economy, Trade and Industry expect output to rise 5.6% in May but decline 4.2% in June, the data showed.
Tension between Washington and Beijing escalated sharply earlier this month after U.S. President Donald Trump's administration accused China of having "reneged" on its previous promises to make structural changes to its economic practices.
Washington later slapped additional tariffs of up to 25% on $200 billion of Chinese goods, prompting Beijing to retaliate.
A slowdown in China hurts Japan because many of its manufactures rely on selling heavy machinery and electronic parts to factories in the world's second-biggest economy.
Japan's economy in the first quarter unexpectedly accelerated but the surprise expansion was mostly caused by imports declining faster than exports, showing both external and domestic demand were weak.
Separate data showed retail sales rose 0.5% in April from a year ago, less than the median estimate for a 0.8% annual increase.
However, that was a slowdown from a 1.0% annual increase in the previous month as shoppers reduced spending on clothes and autos, suggesting some consumers may be turning cautious.