* Energy stocks weigh on New Zealand's benchmark index

* Rio Tinto posts near 5% drop in Q3 iron ore shipments

* Aussie healthcare stocks mark worst intraday in 2 weeks

Oct 16 (Reuters) - Australian shares slipped on Friday as weak iron ore prices pressured heavyweight mining stocks, with waning hopes for additional U.S. fiscal stimulus before the presidential election weighing on market sentiment globally.

The S&P/ASX 200 index was down 0.3% to 6,193.40 by 0003 GMT, after settling 0.5% higher in the previous session.

New Zealand's benchmark S&P/NZX 50 index slipped 0.5% ahead of the election results on Saturday.

An opinion poll showed current Prime Minister Jacinda Ardern from the Labour Party is widely expected to beat her main rival, National Party leader Judith Collins, on the back of her success in tackling the novel coronavirus.

In her campaign, Ardern has vowed to encourage environment-friendly solutions to reduce carbon emissions by phasing out coal-fired boilers as climate change is considered a key issue in the election.

Electricity retailers Contact Energy Ltd and Meridian Energy Ltd were the top losers on the New Zealand index, losing 4.4% and 3.1%, respectively.

In Australia, stocks tracked overnight losses on Wall Street as U.S. President Donald Trump's offer to raise the size of a fiscal stimulus package failed to woo investors, with most believing a deal seemed unlikely before the Nov. 3 election.

The Australian metals and mining index fell 0.3%, weighed down by lower iron ore prices.

Global miner Rio Tinto was down 0.5% after reporting a near 5% drop in third-quarter shipments of the steel-making ingredient. Rival BHP Group Ltd dipped too.

Healthcare stocks gave up 1%, marking their biggest intraday drop in two weeks, with biotech giant CSL Ltd dragging down the sub-index.

Banking stocks were slightly up with the "Big Four" lenders rising between 0.2% and 0.4%.

Auto parts maker GUD Holdings Ltd jumped 4% to a near seven-month, making it one of the top gainers on the benchmark, after Citi upgraded the stock on strong quarterly sales. (Reporting by Anushka Trivedi in Bengaluru; Editing by Subhranshu Sahu)