TOKYO, Aug 18 (Reuters) - Japan's Nikkei share average posted its biggest weekly loss in eight months on Friday, as it fell for a third session amid lingering concerns about China's economic outlook and fears for rising yields.

The Nikkei lost 3.1% for the week, its biggest weekly decline since the week ended Dec. 23. For the day, the index fell 0.55% to close at 31,450.76 in its third straight losing session.

The broader Topix lost 0.70% to 2,237.29 and fell 2.8% for the week.

"The Japanese market slipped for the same reasons as the past few sessions - concerns about China's economy and rising global yields. Japanese equities are easily affected by overseas cues as there are no market moving catalysts at the moment," said Shuji Hosoi, senior strategist at Daiwa Securities.

The overnight benchmark 10-year U.S. Treasury yields hit their highest levels since October and 30-year yields hit 12-year highs on concerns that the Federal Reserve will hold interest rates higher for longer.

The weakness in U.S. equities also weighed on sentiment, said Takamasa Ikeda, senior portfolio manager at GCI Asset Management.

Wall Street ended lower on Thursday, with the Nasdaq posting a 3.4% drop over three days in its steepest three-day fall since February.

"The Nikkei has already reached its peak as the buying momentum from foreign investors has been weakening since July," Ikeda said.

Among individual shares, Uniqlo brand owner Fast Retailing lost 1.15% and was the biggest drag on the Nikkei.

Shares in department store operators, which would benefit from the inflow of Chinese tourists, fell. J.Front Retailing lost 4.31% to become the worst performer on the Nikkei.

Isetan Mitsukoshi Holdings slipped 3.77%.

Heavyweights chip-related shares rose to provide the biggest support to the Nikkei, with Advantest and Tokyo Electron gaining 1.54%% ad 0.68%, respectively.

(Reporting by Junko Fujita; Editing by Rashmi Aich and Sonia Cheema)