At noon AEST on Tuesday, the benchmark S&P/ASX200 index was up 29.3 points, or 0.38 per cent, to 7,709.9, while the broader All Ordinaries had gained 29.7 points, or 0.38 per cent, to 7,917.6.
Overnight, a gauge of activity in the US services sector known as the Services PMI came in stronger than expected, allaying fears about the state of the world's biggest economy.
The US labour market was slowing but not in freefall and a broad suite of indicators showed it remained healthy, ANZ researchers Brian Martin and Daniel Hynes said.
Concerns about a US recession that prompted the selloff on Friday and Monday seem overdone, they said.
Nine of the ASX's 11 sectors were higher at noon, with consumer staples and financials basically flat.
Energy was the biggest gainer, climbing 1.7 per cent as Woodside added 2.1 per cent and Whitehaven Coal rose 2.6 per cent.
In the heavyweight mining sector, lithium developers and goldminers were having a good day, with Pilbara up 3.2 per cent and Newmont climbing 1.3 per cent.
BHP was down 0.2 per cent and Fortescue had dropped 0.8 per cent, while Rio Tinto had edged 0.1 per cent higher.
The Big Four banks were mixed, with Westpac down 0.6 per cent, NAB dipping 0.5 per cent and CBA falling 0.3 per cent, while ANZ had gained 0.4 per cent.
In tech, Audinate had fallen further after Tuesday's 36.3 per cent selloff, dropping 1.3 per cent.
In health care, Neuren Pharmaceuticals was in a trading halt so the company could announce the results of a clinical trial of its potential treatment for Angelman syndrome, a rare genetic disorder.
Indicative pricing showed Neuren shares were set to drop nearly 10 per cent when trading resumes.
In currency, the Australian dollar was buying 65.45 US cents, from 65.05 US cents at Tuesday's ASX close.