The golden west is still Australia's economic powerhouse.
But the gap between the best and worst-performing states in the country appears to be widening, CommSec's quarterly State of the States economic performance report says.
It shows Western Australia is still the strongest of the state economies, even though the resources hotspot has slipped slightly to outrank its rivals in just three of eight criteria.
The Northern Territory continues to lead the rankings on economic activity, closely followed by WA.
"Both economies are likely to hold their top positions over 2013," the report said.
WA leads the way on retail trade, population growth and equipment investment, but ranks second-strongest in economic growth, construction work done and housing finance.
The Northern Territory finished on top of four indicators including economic growth, unemployment, dwelling starts and construction work done.
The report also found Australia's states and territories could be breaking into three distinct groups, with the strong mining economies of WA and the Northern Territory performing strongly, while the more populated states of NSW, Victoria and Queensland require further improvement.
There are worrying signs South Australia and Tasmania could fall further behind the rest of the country, with the Apple Isle ranking last in seven of eight criteria.
The CommSec study showed the Australian Capital Territory was the third strongest economy, just ahead of NSW, Victoria and Queensland.
NSW is the second-strongest on the unemployment scale and third-strongest on population growth while Victoria is the strongest in terms of housing finance and dwelling starts.
Queensland posted high rankings in equipment investment, construction work done and retail spending.