* Nikkei creeps lower on profit-taking after Thursday bounce
* Nerves before U.S. jobs data weigh on market
* Pioneer drops, Mitsubishi Rayon shoots higher
TOKYO, Aug 7 (Reuters) - Japan's Nikkei stock average edged lower on Friday as investors nervous before key U.S. jobs data locked in profits, with Honda Motor Co and other automakers slipping.
Pioneer Corp lost 4.3 percent after the consumer electronics maket reported a quarterly loss due to sluggish car sales and a stronger yen, and stuck to its outlook for a sixth straight year in the red.
Wall Street slipped as investors turned cautious a day before the July employment data and took profits in the wake of recent strong gains, and market analysts said spillover from this move was prompting sales of Japanese shares as well.
"Nobody knows what the jobs data will do to the market. The U.S. basically stalled ahead of this and Japan is likely to do the same," said Masayoshi Okamoto, head of dealing at Jujiya Securities.
"We're certainly not heading into a downtrend, but we've been gaining for five months now mainly on expectations that company results will improve and it's hard to know if we can maintain this momentum into the rest of the year. Rises will be tough."
The benchmark Nikkei shed 0.7 percent or 67.64 points to 10,320.45 after hitting a 10-month closing high of 10,388.09 on Thursday.
The broader Topix lost 0.7 percent to 950.99.
The U.S. economy is expected to have lost 320,000 nonfarm payroll jobs in July, a hefty number but still an improvement over last month's drop of 467,000, while the unemployment rate is expected to have risen to 9.6 percent.
Analysts said that while expectations are not as high as they were last month, when the figures were an unhappy surprise that sent markets tumbling, some weak U.S. economic data this week has cooled investor optimism about the speed of economic recovery.
The U.S. service sector contracted in July at a faster pace than in June, with the Institute for Supply Management's services index falling to 46.4 last month from 47.0 in June -- below a median forecast for a rise to 48.
"Part of the problem with last month's jobs data was that people were expecting too much, but I think this time they're a bit more realistic," said Nagayuki Yamagishi, a strategist with Mitsubishi UFJ Securities.
"Even if the figures aren't that good, the market's prepared to an extent. Once the data's out we can move on."
Carmakers and related firms were some of the biggest losers on Friday after Thursday's bounce, partly on expectations that the U.S. "cash for clunkers" sales incentive would be extended.
Honda fell 1.9 percent to 3,060 yen and Toyota Motor also lost 1.9 percent, to 4,050 yen.
Car parts maker Denso Corp lost 1.8 percent to 2,800 and tyre maker Bridgestone Corp, which announces earnings later on Friday, shed 1.2 percent.
But Mitsubishi Rayon shot up 4.3 percent to 269 yen after the Nikkei business daily reported that the firm plans to set up a joint venture with Saudi Basic Industries Corp (Sabic) to produce material used for acrylic glass in Saudi Arabia. (Reporting by Elaine Lies; Editing by Chris Gallagher)