* Aussie gold sub-index hits record high

* Tech index leads decline, down 2.8%

* BHP Group among top losers on benchmark

July 22 (Reuters) - Australian shares fell on Wednesday after notching their best session in more than a month, as U.S. President Donald Trump's comments regarding a surge in the country's coronavirus cases weighed on investor sentiment.

The S&P/ASX 200 index declined 0.9% to 6,100.7 by 0109 GMT, after rising 2.6% on Tuesday - its best since June 16.

Trump on Tuesday told reporters that the virus would probably get worse before it gets better, in one of his first recent acknowledgements of how bad the problem has become.

Tech stocks led the fall with a 2.8% slide. Buy-now-pay-later firm Afterpay traded in the red after two days of sharp gains.

Heavyweight BHP Group was one of the top losers on the benchmark index, slipping up to 3.3%. The mining giant flagged waning demand for its key commodities as a fallout of COVID-19 in its quarterly production update on Tuesday.

The gold sub-index hit a record high as bullion prices rose to their highest since September 2011, propelled by a softer U.S. dollar and expectations of more stimulus to resuscitate pandemic-hit economies.

Resolute Mining jumped more than 6% and was the top gainer after the company said it would meet its full-year guidance.

The energy index hit a near two-week high after overnight gains in oil prices. Beach Energy, up 5.4%, was one of the top percentage gainers despite a drop in quarterly production volume.

In company news, QBE Insurance Group warned of a statutory loss for the first half, largely due to coronavirus-related claims, while rare earths miner Lynas Corp said fourth-quarter output nearly halved.

QBE shares rose up to 2.8% and were among the top gainers on the financial index, which was down 0.2%.

In New Zealand, the benchmark S&P/NZX 50 index rose 0.26% to 11,767.4. (Reporting by Arundhati Dutta in Bengaluru; Editing by Subhranshu Sahu)