The Australian currency opened in a better position today, thanks to news its primary trading partner, China, has overtaken Japan as the world's second-largest economy.

At 7am (AEST) today, the local unit was exchanging at $US0.8982/85, an increase from Monday's finish of $US0.8939/44.

Since 5pm yesterday, the domestic dollar traded from $US0.8890 to $US0.8994.

A solid night on Asian equity markets and reports that China might be moving away from buying US government debt bolstered the Aussie, according to Commonwealth Bank vice-president of institutional banking and markets Tim Kelleher.

"(The Australian currency) had a strong night, it rallied," Mr Kelleher said.

"China had a very strong close in the share market yesterday, so that helped."

The Shanghai composite index finished its session 2.11 per cent stronger at 2661.708 points yesterday following news that China is now the world's second-largest economy.

Japan experienced sluggish quarterly economic growth in the April-June period with an annualised pace of only 0.4 per cent, far below the annualised 4.4 per cent expansion in the first quarter.

The Chinese economy, on the other hand, was forecast to grow 9.2 per cent in the third quarter and 8.0/8.5 per cent in the last three months of the year.

Mr Kelleher predicted the upward trend for the Australian dollar to continue today, with gains capped at $US0.9100.

During the trading day, the Central Bank is expected to release the minutes of its August 3 board meeting, at which it opted to leave the cash rate on hold at 4.5 per cent.