July 7 (Reuters) - Australian shares rose on Wednesday, lifted by the healthcare and technology sectors, while Challenger Ltd jumped after two U.S. companies bought a stake in the investment manager.

The S&P/ASX 200 index climbed 0.26% to 7,280.7 by 0020 GMT and was on track for a third session of gain in four.

Challenger soared more than 13% to become the top gainer on the benchmark index, after retirement services provider Athene Holding Ltd and private equity firm Apollo Global Management acquired a 15% stake in the company.

Healthcare stocks jumped 1.9% after two straight sessions of falls and were set for their best session in nearly three weeks.

Biotech company CSL Ltd and medical device maker Resmed Inc advanced 2% and 2.1%, respectively.

Tech stocks advanced 1.6%, tracking their peers on Wall Street, and were set for their best day in about two weeks.

Buy-now-pay-later firm Afterpay advanced 1.4%, while artificial intelligence company Appen rose 2%.

Gold stocks gained more than 1% as bullion prices firmed on retreating U.S. bond yields.

Top independent gold miner Newcrest Mining advanced more than 1%.

Meanwhile, local media reported a two-week COVID-19 lockdown in the country's largest city of Sydney would be extended by another week to July 16.

Elsewhere, Japan's Nikkei was down 1.35%, while S&P 500 E-minis futures fell 0.14%.

New Zealand's benchmark S&P/NZX 50 index fell 0.6%, weighed down by losses in healthcare and consumer stocks. (Reporting by Soumyajit Saha in Bengaluru; Editing by Subhranshu Sahu)