TOKYO, Sept 6 (Reuters) - Japan's Nikkei share average inched up on Tuesday, as investors bought back stocks after four straight sessions of losses, underpinned by gains in Uniqlo clothing shop owner Fast Retailing and heavyweight chip makers.

The Nikkei index inched up 0.02% to 27,624.96 by the midday break, after slipping into the negative territory momentarily. The broader Topix was 0.04% lower at 1,927.97.

The Nikkei was firm despite losses on the European stocks overnight, after the euro dropped below 99 cents for the first time in 20 years and European gas prices surged after Russia said its main gas supply pipeline to Europe would stay shut.

"Investors bought back beaten down stocks, particularly chip shares," said Shoichi Arisawa, general manager of the investment research department at IwaiCosmo Securities.

"Japan's economy is supported by various government measures and stable compared with other countries, which gives a comfort to investors."

Fast Retailing gained 0.27% and provided the biggest support to the Nikkei.

Chip giants Tokyo Electron and Advantest edged up 0.28% and 0.52%, respectively.

Overall, Japanese equities are underpinned by expectations of domestic growth driven by various economic measures, including further easing of border controls after tourism demand was hurt by the COVID-19 outbreak, Nomura Securities strategist Maki Sawada said.

"But caution about slowdown of the U.S. economy capped further gains."

Unitika surged 8.71%, even after the textile maker was announced to be excluded from the Nikkei 225 in a regular reshuffle.

Maruha Nichiro fell 1% after the fishing company was excluded from the Nikkei, while Hoya jumped 2,73% after the eyeglass lenses maker was added to the index.

(Reporting by Junko Fujita; Editing by Rashmi Aich)