TOKYO, Nov 6 - A key indicator of Japanese economic conditions rose in September, government data showed on Thursday, fuelling hopes for an upbeat reading in July-September growth figures due next week. The diffusion index of leading economic indicators stood at a preliminary 80.0 on a scale of 100, up from a revised 54.5 in August, the Cabinet Office said. The index -- compiled using data such as the number of new job offers, consumer sentiment and Tokyo share prices -- was well above the critical 50 level, which marks the difference between expansion and contraction in the coming months. The coincident index, which indicates current economic conditions, was at a preliminary 83.3 in September, up from a revised 50.0 in August. The improvement is good news for Prime Minister Junichiro Koizumi ahead of a general election on Sunday and adds to optimism that Japan's gross domestic product (GDP) probably grew in the July-September quarter thanks to buoyant demand for its exports. GDP figures are due on November 14. Upbeat industrial output figures and a recovery in capital spending is seen offsetting sluggish spending by consumers, who are worried about weak job conditions. The Cabinet Office revises the indices several times before issuing final figures.//www..com