Japan said Thursday that growth halved in the three months to September, a worrying sign for Tokyo's bid to kick-start the world's third-largest economy.

Official data showed the economy expanded by 0.5 percent in the quarter, slightly higher than economists' expectations but a marked slowdown from 0.9 percent growth in the previous quarter.

On an annualised basis, growth slumped to 1.9 percent from 3.8 percent in the previous three months -- showing the pace of growth if the data were stretched across a full year.

The earlier growth outcome was largely a result of a boost in exports owing to a sharply weaker yen, while stubbornly low consumer spending also showed signs of picking up.

The long-lagging economy has lately been outpacing other G7 economies as a policy blitz led by Prime Minister Shinzo Abe, dubbed "Abenomics", helped drive down the currency and stoked optimism over Japan's prospects.

However, analysts have been warning that the program -- a mix of big government spending and central bank monetary easing -- was not enough on its own without promised economic reforms which have yet to be seen. (AFP)