Business: Asian markets subdued by falling oil prices

The price of US crude oil dropped more than 3% overnight, while Brent crude was back near 11-year lows on reports that Iran plans to increase exports once sanctions are removed, which would add to the global supply glut.

Lower energy shares across Asia weighed on benchmark indexes. 

Japan's Nikkei 225 index was down 0.1% to 18,850.17 in morning trade.

"Oil prices look likely to continue in their depressed state if Iran is able to ramp up its exports at such a rapid rate," said market analyst Angus Nicholson at trading firm IG in a note on Tuesday.

Iran intends to increase exports by 500,000 barrels per day once the economic sanctions are removed, according to reports.

Toshiba's restructuring

Meanwhile, shares of Toshiba rose by 0.6% on a local report that the struggling electronics giant planned to ask for an additional $2.5bn (£1.7bn) in credit to fund its large-scale restructuring.

The company is reeling from a $1.3bn accounting scandal earlier this year.

Chinese shares headed higher in early trade with the Shanghai Composite up 0.4% to 3,546.38, while Hong Kong's Hang Seng index was higher by 0.1% to 21,945.33.

In Australia, the benchmark S&P/ASX 200 was up 0.6% to 5,238.80 after reopening from public holiday on Monday.

Bucking the trend were shares of Woodside Petroleum, up 0.1% despite the drop in oil prices.

South Korea's Kospi index was down 0.7% to 1,949.56, following the previous session's losses.