IMF downgrades global growth again

The International Monetary Fund has made further across-the-board cuts to its global economic growth forecasts.

Six years on from the global financial crisis, the IMF says a return to a robust and synchronised global expansion remains elusive.

"Moreover, downside risks to the world economy appear more pronounced than they did just a few months ago," the IMF said, releasing its latest World Economic Outlook.

It says the sources of slower growth are diverse - ranging from commodity price declines, to overhangs from past rapid credit growth, to political turmoil.

The global economy is now expected to grow by 3.1 per cent this year and 3.6 per cent in the next, both 0.2 percentage points lower than previously forecast.

The Australian economy is expected to grow by 2.4 per cent in 2015 and 2.9 per cent in 2016, slightly weaker than predicted six months ago.

That reflects the impact of lower commodity prices and resource-related investment, albeit partly offset by supportive interest rates and a weaker Australian dollar.

Notably, growth in emerging and developing economies is projected to slow for a fifth year in a row.

The Washington-based institution expects China - Australia's number one trading partner - to slow to 6.8 per cent in 2015 and 6.3 per cent in 2016.

However, it assumes the recent steep decline in its share market will have only a modest effect on Chinese consumption, reflecting the small share holdings among households.