TOKYO (Reuters) – Japanese manufacturers are the most optimistic about economic conditions in more than two years, a Reuters poll shows, suggesting the Bank of Japan's influential tankan survey due next month will similarly improve.

A close correlation between the Reuters poll and the BOJ tankan report suggests the central bank survey will show that big manufacturers' sentiment for the second quarter rose to around zero, a two-year high, from minus 14 in March.

The BOJ uses its tankan report to guide policy but the improvement in business sentiment is unlikely to prompt any new action from the central bank because it largely reflects its expectations for an economy showing a moderate recovery, economists said.

Strong export growth to fast-growing Asia is lifting manufacturers' sentiment. In a sign a pickup in the economy is broadening, the Reuters poll also showed that service-sector firms were far less pessimistic than three months earlier and that they would become optimistic in the next three months.

"The rebound in external demand is proceeding much better than I expected," said Yuichi Kodama, an economist at Meiji Yasuda Life Insurance.

"Capital expenditure will improve in the second half of the year because production is doing so well. But we are still in deflation, and this leaves room for the government to request more of the BOJ."

The BOJ tankan is due to be released on July 1.

The manufacturers' sentiment index for June in the Reuters Tankan rose by 17 points from March to plus nine, its highest level since February 2008.

It shows that sentiment turned optimistic during the April-June quarter and back to levels experienced before the collapse of Lehman Brothers in September 2008. The Reuters poll also said the sentiment index is expected to climb a further five points to plus 14 in September.

The last BOJ tankan in March showed pessimism was still greater than optimism as the index for large manufacturers was minus 14.

Meiji Yasuda Insurance's Kodama said that based on the Reuters poll outcome, he expects the BOJ tankan to show that optimism and pessimism were evenly matched, taking the index to zero.