Japan's Nikkei share average struck a fresh four-week low on Wednesday as weak U.S. manufacturing data and construction spending added to concerns about a global economic slowdown.

The Nikkei <.N225> fell 0.8 percent to 8,702.34 points, breaking below support at its 75-day moving average of 8,768.78, leaving it on track to end down for the fifth straight session.

Traders said bearish bets on China-related stocks also were pulling the market down. Doubts about the country's growth prospects on recent disappointing data pushed down the Nikkei China 50 <.NCHN>, an index of 50 Japanese companies with high exposure to China, by 1.2 percent.

"Investors in the Japanese market are primarily worried about China right now, although the U.S. data made investors more keen to watch what happens with the jobs data out on Friday," said Mass Odd, chief investment officer at Sumitomo Mitsui Investment Trust.

Odd said that expectations that the European Central Bank will act to lower borrowing costs for countries such as heavily indebted Spain and Italy at its meeting on Thursday were largely priced into the market.

Komatsu Ltd <6301.T> dropped 2.9 percent and Hitachi Construction Machinery Co Ltd <6305.T> lost 2.9 percent after U.S. construction spending in July fell by the most in a year.

Concerns about flagging growth in the world's largest economy were further reinforced after U.S. manufacturing contracted for a third straight month in August.

However, recent disappointing data has fuelled hopes of further stimulus from the U.S. Federal Reserve. Some market watchers hope it will announce at its meeting next week a third round of bond purchases, or "quantitative easing".

"For those in the market that are pricing in QE3, hopefully the jobs data is not too good to take it off the Fed's table," said Stefan Woodall, director of equity cash sales at Credit Suisse in Tokyo.

"But the key message for me is that the data in the U.S. is better in parts... as far as autos and housing are concerned, the recession is over."

Automakers outperformed the broader market on strong year-on-year U.S. sales in August, with Toyota Motor Corp <7203.T> advancing 0.8 percent after reporting a 46 percent increase and Honda Motor Co <7267.T> inching up 0.4 percent after seeing sales grow a massive 59.5 percent.

However, Nissan Motor Co <7201.T> slipped 1.1 percent after its sales increased by just 7.6 percent.

The broader Topix <.TOPX> dropped 0.9 percent to 720.24 in moderate trade, with volume at 47.8 percent of its full-day 90-day average.

A RARE FILLIP FOR UTILITIES

Bucking the market, Chubu Electric Power Co Ltd <9502.T> rose 3.8 percent after the utility said it would begin paying an annual dividend of 50 yen in the year ending March 2013, despite forecasting an operating loss of 45 billion yen ($574 million) in the same period.

"Chubu is very aware that it needs to entice or appease its shareholders because its share price has fallen so much it will have to issue more bonds," Odd of Sumitomo Mitsui Investment Trust said.

"It is also the electric power company that had the lowest reliance on nuclear power so it has a more stable income than the others."

Chubu's gains left the electric and gas subindex <.IEPNG.T> flat, outperforming the wider market. However, the sector is down 26 percent this year after falling 44 percent in 2011, as utilities have been hit by soaring bills for oil and natural gas as most of Japan's nuclear reactors remain offline.

Elsewhere, shares of cash-strapped computer services provider NEC Corp <6701.T> slid 5.3 percent after a Reuters report that the company would sell its entire stake in China's Lenovo Group Ltd <0992.HK> for about 18 billion yen ($230 million).

($1 = 78.3900 Japanese yen)

(Additional reporting by Dominic Lau; Editing by Kim Coghill)