Asian shares edged higher Tuesday but sentiment was cautious, after global shares faltered overnight on weak corporate results and outlook, and with Asia's corporate reporting season under way.

South Korea's POSCO, backed by Warren Buffett, will kick off the earnings season Tuesday for major Asian steelmakers on an expected weak note. The world's fourth-biggest steelmaker is likely to post a third consecutive loss, dogged by weak China demand and prices.

The MSCI index of Asia-Pacific shares outside Japan was up 0.2 percent, with Australian shares  adding 0.5 percent and South Korean shares opening 0.1 percent higher, Reuters reported.

Japan's Nikkei average opened 0.6 percent higher as the yen weakened broadly and supported exporters.

The dollar rose to 80.02 yen, its highest since July 6, with expectations for further monetary easing from the Bank of Japan later this month underpining the Japanese currency.

The yen also weakened to a 5-1/2 month low of 104.59 yen against the euro and a 1-month low of 82.68 against the Australian dollar.