The Australian share market has opened lower as investors appeared to be spooked by renewed concerns about the trade conflict between China and the United States.

The benchmark S&P/ASX200 index was down 28.9 points, or 0.46 per cent, to 6,306.9 points at 1015 AEST on Monday, while the broader All Ordinaries was down 30.0 points, or 0.47 per cent, to 6,397.2.

The Wall Street Journal on Monday cited a source saying China was considering cancelling trade talks with the US after President Donald Trump tweeted overnight that he would hike tariffs on $US200 billion worth of Chinese goods this week.

All sectors of the ASX were in negative territory in the first 15 minutes of trade on Monday.

Tech shares were leading losses – collectively down 1.15 per cent – followed by the consumer discretionaries segment, which fell 0.91 per cent.

The big four banks were mixed as Westpac shed 1.28 per cent to $27.09 after reporting its first-half profit fell 22 per cent.

The Aussie dollar is buying 69.71 US cents, from 69.95 US cents on Friday.