By Tetsushi Kajimoto
TOKYO (Reuters) - Confidence at Japanese manufacturers fell the most in nearly two years in September as a tax increase hit the economy harder than expected, a Reuters poll showed, suggesting further difficulty for the struggling recovery.
The worsening sentiment in the monthly Reuters Tankan, with only a feeble improvement forecast for December, bodes ill for the Bank of Japan's quarterly tankan survey, which had been forecast to rebound in the third quarter.
Service-sector sentiment edged up but was forecast to decline again.
This frailty in business confidence and the shaky outlook could raise in coming months the pressure on the BOJ to ease policy further and complicate Prime Minister Shinzo Abe's decision on whether to raise the national sales tax again.
"The effects of the decline in demand have proved larger than expected" after the April tax hike, said an executive at a machinery maker. A transport equipment producer blamed the higher tax for cooling demand and worsening business conditions.
The managers, who responded anonymously to the Reuters survey, also complained about weak external demand, notably in Asia and Europe, and uncertainty over geopolitical risks that weigh on the outlook.
The Reuters Tankan, which is strongly correlated with the central bank's closely watched poll, surveyed 486 big Japanese companies, of which 285 replied, between Aug. 29-Sept. 12.
The sentiment index for manufacturers fell to 10 in September from 20 in August and down from 19 in June. It is forecast to rise to 16 in December.
It was the first decline in four months and the biggest since October 2012. At that time, business sentiment was plunging amid Chinese boycotts of Japanese products and violent protests after Japan nationalized islets in the East China Sea that are also claimed by Beijing.
This time, the loss of confidence comes after a slew of weak data, including soft factory output and falling household spending, has cast doubt over the recovery of the world's third-biggest economy.
The last BOJ tankan found the mood among big manufacturers had worsened in the three months to June but was expected to improve in July-September. The BOJ tankan is due next on Oct. 1.
The Reuters Tankan service-sector index rose to 22 in September from 19, the first increase since June, but still well below 29 that month. It is forecast to fall back to 20 in December.
The survey indices subtract the percentage of companies saying conditions are improving from that of companies saying conditions are worsening. A positive number means optimists outnumber pessimists.
Abe raised the sales tax to 8 percent from 5 percent in April in a bid to curb Japan's runaway government debt, knocking the economy into its deepest contraction since the global financial crisis in the second quarter.
Around December he is to decide whether to proceed with a plan to raise the tax to 10 percent next year. Abe said on Sunday he remained "neutral" on whether to raise the tax, adding that decision would hinge on the strength of economic indicators, including for the July-September quarter.
With the recovery sputtering and inflation appearing stalled well below the BOJ's target of 2 percent, market speculation is growing that Abe may order a burst of government spending and the BOJ may oblige with further monetary stimulus to bolster the economy enough to allow the tax hike to go ahead.
The yen has fallen to a six-year low against the dollar in recent days, but it has not yet given much of a boost to exporters, while importers, such as materials firms, are struggling to pass on rising import costs.
(Editing by William Mallard and Clarence Fernandez)