The Australian economy might have registered its biggest quarterly contraction since the dark days of the global financial crisis. But NSW, and especially Sydney, is bucking the downbeat trend.

The broadest quarterly measure of a state's economic performance – state final demand – rose in NSW during the three months to September and was up by 5 per cent over the year.

That was the best result in six years and twice the rate of the next strongest state, Victoria (2.5 per cent).

Economic conditions in Western Australia are especially weak. State final demand there shrank by 3.8 per cent in the September quarter to be down a huge 9.5 per cent over the year.