The economic outlook in Australia has improved at an above trend pace, a study released on Wednesday by the Westpac Banking Corp and Melbourne Institute found.

The annualized growth rate of the Westpac Melbourne Institute Leading Index, which indicates the likely pace of economic activity three to nine months into the future, was 3.9 percent in November 2012, above its long term trend of 2.8 percent, Westpac said on Wednesday.

However, the annualized growth rate of the Coincident Index, which measures current growth, was 2.7 percent, below its long- term trend of 3.0 percent.

Westpac chief economist Bill Evans said the index was sending a more optimistic growth signal than expected.

"Over the course of the last six months, the annualized growth rate in the Index has increased from 1.5 percent (well below trend) to 3.9 percent (above trend)," Evans said in a statement on Wednesday.

"Our current forecast for GDP (gross domestic product) growth over the course of 2013 is 2.75 percent, below trend growth in the economy."

However, there is likely to be a modest pickup in non-mining investment and residential construction in 2013, he said.

The bank also expects a moderation in consumer spending and a considerable slowdown in mining investment.