Australian shares struggled for direction on Thursday as gains in healthcare and banking sectors countered losses in miners and energy firms, while financials and utilities helped New Zealand stocks climb for a third straight session.

The S&P/ASX 200 index was flat at 6,886.20 by 2345 GMT, after shedding 0.5% on Wednesday.

Miners were the top losers, shedding as much as 1.6% after three straight sessions of gains, as top iron ore miners dragged.

Fortescue Metals Group was down up to 2.6% as it hiked its cost estimate and delayed the time frame for its key Iron Bridge Magnetite project in Western Australia.

After market hours on Wednesday, Rio Tinto reported its best annual earnings since 2011 and declared a record dividend payout. Its shares fell as much as 2.6% on Thursday, on track to snap a three-day winning streak.

Energy stocks fell up to 1.2%, dragged by a 3.7% drop in Woodside Petroleum after Australia's top independent gas producer posted a 58% slump in its annual underlying profit.

Retail conglomerate Wesfarmers declined up to 3.1% after it warned of a moderation in retail sales growth at its Bunnings and Officeworks divisions from March.

Among gainers, the healthcare sector was the biggest boost to the benchmark, adding 3.2% on the back of biotech firm CSL.

CSL shares jumped 5% after the company reported a rise in half-year profit as demand for vaccines and blood plasma products increased.

Financials were up 0.5%, with Australia and New Zealand Banking Group gaining as much as 4.4% to hit its highest since February last year, after it reported a rise in first-quarter profit and said it was well-positioned for the rest of the year.

New Zealand's benchmark S&P/NZX 50 index gained as much as 0.9% to 12,785.68, with financials and utilities contributing the most.