* Drugmakers, retailers and railways lead losses

* Investors close positions ahead of U.S. job data

* Rakuten, Konica Minolta and Ricoh down after earnings

* Softbank gains after share buyback plan

By Hideyuki Sano

TOKYO, Aug 7 (Reuters) - Japan's Nikkei share average edged down on Friday as investors took profits from recent high flyers such as drugmakers, railways and retailers ahead of U.S. jobs data due later in the day.

While Japanese companies' earning results for April-June have been generally solid, concerns over a slowing growth in China and possible fallout from a likely U.S. rate hike kept investors cautious.

The Nikkei average dipped 0.3 percent to 20,610.18 while the broader Topix fell 0.4 percent to 1,667.65, though it is still up 0.5 percent so far this week.

Leading the losses were shares oiented primarily at domestic demand, which had been outperforming for weeks as investors shunned exporters and other shares seen as more susceptible to a possible global slowdown.

Retailer Seven & I fell 1.4 percent, the biggest decliner among the core 30 of the largest companies.

The Tokyo Stock Exchange's retailers subindex also fell 1.3 percent. The subindex has risen 37 percent so far this year, one of the best performer in the Tokyo market.

Drugmakers, which have also risen more than 35 percent so far this year, lost 1.5 percent. The land transport subindex, which includes railway companies and truck companies, fell 1.9 percent.

"This time the U.S. payroll data will be a big event to see whether the Fed will raise rates in September," said Masahiro Ayukai, senior investment strategist at Mitsubishi UFJ Morgan Stanley Securities.

"So it is natural some market players are closing their positions ahead of data," he added.

Disappointment over earning results hit some other shares.

Rakuten fell 8.6 percent after its quarterly earnings fell short of strong market expectations.

Ricoh and Konica Minolta, both manufacturer of printers and other products, fell sharply following fall in net profits in the quarter to June. Ricoh fell 6.1 percent and Konica Minolta 8.4 percent.

Sumco, manufacturer of silicon wafer products, also failed to keep initial losses after its announcement of profit growth due to strong demand for products for smart phone and dividend hikes. It fell 4.5 percent, erasing earlier gains of 7.9 percent.

There are growing worries that sales of smart phones may be slowing globally, hitting many Japanese suppliers of components to companies such as Apple and Samsung Electronics .

On the other hand, Softbank rose 4.5 percent after it announced a share buyback plan and fairly upbeat earnings.

(Editing by Eric Meijer)