Japan's Nikkei share average tumbled to a six-week low on Monday as global oil prices extended their decline, adding to nervousness ahead of an expected US interest rate hike this week.
The Nikkei ended 1.8 per cent lower at 18,883.42, the lowest closing level since November 2, as investors sold riskier assets.
The broader Topix dropped 1.4 per cent to 1,527.88, and the JPX-Nikkei Index 400 fell 1.4 per cent to 13,746.26.