* Crown Resorts top gainer on benchmark

* Energy stocks mark biggest one-day gain in over two weeks

* Insurers fall due to flash floods in Australia's east coast

March 22 (Reuters) - Australian shares rose on Monday, led by gains in energy and healthcare stocks, while beleaguered casino operator Crown Resorts spearheaded gains on the benchmark index after receiving Blackstone's buyout offer.

The S&P/ASX 200 index closed 0.7% higher at 6,752.5. The benchmark fell 0.6% on Friday.

Crown Resorts closed over 20% higher as the top percentage gainer on the benchmark, after it received a A$8.02 billion ($6.2 billion) conditional buyout proposal from U.S. private equity giant Blackstone.

Gaming and leisure stocks rose, with Tabcorp ending the session at a 16-month high, while Aristocrat Leisure gained 1.5% on news of Crown's proposed buyout.

Energy stocks were the best performers on the index, gaining 2.8% to mark its biggest one-day gain in over two weeks.

Woodside Petroleum and Santos rose 2.5% and 2.4%, respectively.

Healthcare stocks posted significant gains, driven by a 2.5% jump in sector heavyweight CSL.

"The healthcare sector has been suffering through COVID-19 with no real direction. So I think we are seeing a little bit of bargain hunting creeping in," said Henry Jennings, senior analyst at Marcustoday Financial newsletter.

Ramsay Health Care gained 2.1%, while medical device company Polynovo hit an over two month high.

Heavy rains along Australia's east coast over the weekend brought the worst flooding in half a century in some areas, authorities said on Sunday, forcing thousands of people to evacuate and causing significant property damage.

This raised worries of increased claims for insurers, with Insurance Australia Group and QBE Insurance Group slumping 2.3% and 3%, respectively.

Insurer Suncorp Group, which has received 1,300 claims so far, said it was too early to estimate the costs from the flooding.

New Zealand's benchmark S&P/NZX 50 index closed 1.5% lower at 12,329.09, with dairy processor Synlait Milk being the top loser. (Reporting by Harish Sridharan in Bengaluru; Editing by Rashmi Aich)