Sept 2 (Reuters) - Australian shares saw their biggest fall in about one-and-a-half months on Thursday, hurt by a slide in global miner BHP Group Ltd and other mining stocks, with persisting worries around the coronavirus denting sentiment further.

The S&P/ASX 200 index fell 1.1% to 7,444.3 by 0046 GMT and was set to decline for a second straight day.

Miners, down 3.1%, extended their losses for a third straight day and hit their lowest in one-and-a-half weeks.

BHP Group Ltd, which is presently trading ex-dividend, dropped as much as 7.4% to notch its biggest one-day drop since May 1, 2020.

The world's biggest miner on Aug. 17 said it will pay a final dividend of $2 (A$2.71) per share, totalling $10.1 billion.

Weighing on miners further were weaker iron ore prices, with Rio Tinto Ltd and Evolution Mining falling 0.7% and 1.5%, respectively.

Biotechnology company CSL Ltd and Australia's biggest supermarket chain Woolworths Group, which are both trading ex-dividend, dropped 2% and 2.2%, respectively.

Meanwhile, Australian authorities extended on Wednesday a lockdown in the country's second most populous city, Melbourne, for another three weeks, shifting their focus to rapid vaccination drives.

Among other stocks and sectors, the gold index fell, with Ora Banda Mining Ltd shedding 5% and Geopacific Resources losing as much as 6.3%.

Heavyweight financials dropped 0.4%, with health insurer NIB Holdings dropping 2.7% and wealth manager Perpetual Ltd down 2.3%.

Across the Tasman Sea, New Zealand's benchmark S&P/NZX 50 index was down 0.3% at 13,206.21, dragged by industrials and healthcare stocks. Seafood firm Sanford Ltd was down 5.7% to be the top loser on the index.

Elsewhere, Japan's Nikkei was up 0.1%, while the S&P 500 E-minis futures were down 0.1%.

(1 Australian dollar = $0.7372)

(Reporting by Harish Sridharan in Bengaluru; editing by Uttaresh.V)