Australian shares have hit a fresh record high amid surging global investor optimism ahead of a looming US-China trade deal.

The benchmark S&P/ASX200 index was up 52.1 points, or 0.75 per cent, at 6,955.8 points at noon AEDT on Tuesday after reaching a record high of 6,961.2 in morning trade.

The previous record peak of 6,933.2 was reached last week.

The broader All Ordinaries index was also up 52.1 points at midday on Tuesday, a rise of 0.74 per cent to 7,072.3 points.

CommSec analyst James Tao says the local market followed the US higher on global optimism about improving US-China relations.

The US taking China off its currency manipulator list ahead the two giant economies signing a phase-one trade deal this week was a good sign for global economic activity, Mr Tao said.

“It paints a much prettier picture for markets worldwide,” he said.

Stephen Innes, Asia Pacific market strategist at AxiTrader, said the US-China trade deal had been a massive trigger for tech investment in the US, propelling tech stocks higher in America.

In Australian the health care sector was performing strongly.

It was driven higher by biotechnology heavyweight CSL, which hit an all-time high of $299.80 in morning trade. CSL was up $5.21, or 1.77 per cent, at $299.71 at noon.

Steel product maker BlueScope Steel was another top performer. It gained 47 cents, or 3.03 per cent, to $15.96.

In the retail sector, both Woolworths and Coles were trading higher on renewed consumer sentiment.

Woolworths was up 63 cents, or 1.68 per cent at $38.06. Its rival Coles was up 32.5 cents, or 2.1 per cent, at $15.795.

Tech stocks emulated the increases of peers in the US overnight.

Appen was one of the best local performers. It gained 31 cents, or 1.29 per cent, to $24.31.

The big four banks were all up. CBA had the best gain of the group. Its price was up 89.5 cents, or 1.09 per cent, at $82.48.

Meanwhile, goldminers were one of the few groups with an unhappy start to the ASX trading day.

Newcrest Mining fell 54 cents, or 1.76 per cent, to $30.21.

The Australian dollar was buying 69.04 US cents, down from 69.15 US cents at Monday’s close.