TOKYO, Oct 6 (Reuters) - Japan's Nikkei share average traded lower on Friday, led by the declines in heavyweight chip-related stocks, as investors awaited U.S. jobs report later in the day for clues on the Federal Reserve's interest rate path.

The Nikkei index was down 0.25% at 30,998.80 by the midday break. The index was volatile this week, losing 2.7% on Wednesday and gaining 1.8% in the previous session.

For the week, the Nikkei is on course to fall 2.7%.

"The market rebounded sharply in the previous session from declines earlier in the week. But it was not strong enough to erase those losses," said Shigetoshi Kamada, general manager at the research department at Tachibana Securities.

"It was hard for investors to make active buying ahead of the U.S. nonfarm payrolls data."

Interest-rate sensitive large growth stocks fell, with chip-making equipment maker Tokyo Electron down 2.66% and chip-testing making equipment maker Advantest slipping 2.62%. Technology investor SoftBank Group fell 0.64%. The broader Topix was, however, up 0.2% to 2,268.23. Takeda Pharmaceutical rose 1.72% to become the biggest boost for the Topix. Trading firm Mitsubishi Corp rose 1.46%.

Monex Group jumped 10.17% after surging to its daily limit high in the previous session, as the online brokerage agreed to make a capital alliance with mobile phone operator NTT Docomo.

Onward Holdings dropped 7.66% even as the apparel group raised its annual profit forecast and increased dividend payouts.

The brokerage sector rose 2.11% to become the top performer among the Tokyo Stock Exchange's 33 industry sub-indexes.

Energy explorers lost 1.7% to become the worst performing sector.

(Reporting by Junko Fujita; Editing by Rashmi Aich)