Andrada Mining. Share News (ATM)

By Aditya Soni

March 29 (Reuters) - Australian shares were slightly weakerin thin pre-holiday trade on Thursday, as softer iron ore pricesweighed on materials stocks and following a see-saw session onWall Street.

The S&P/ASX 200 index fell 0.3 percent, or 16.40points, to 5,773.100 by 0120 GMT, having declined 0.7 percent onWednesday. The benchmark was on track to post a decline of about4 percent for the month, its biggest since January 2016.

Australian and New Zealand markets are closed on Friday andMonday for public holidays.

U.S. stocks finished lower in a volatile session onWednesday, dragged by losses in online retailer Amazon.comwhich fell after a report showed U.S. President DonaldTrump wanted to rein in the company.

Investors are trying to minimise their losses ahead of thelong weekend, said Christopher Conway of the Australian StockReport.

A fall in iron ore prices led to weakness in materialstocks, especially miners, with the Australian metals and miningindex declining 1.2 percent to its lowest in more thanthree months.

Global miner BHP slipped 1.5 percent to its lowestin nearly three-weeks, while its rival Rio Tinto Ltdslid 0.8 percent to its lowest since Dec. 20.

Consumer staples were also under pressure, withAustralian-listed shares of dairy firm a2 Milk Company Ltdleading the losses.

Nestle, the world's biggest packaged food maker,launched a brand of infant formula that uses the protein madepopular by a2 Milk Company, The New Zealand Herald reported. [https://bit.ly/2pMYtQR]The New Zealand Herald added that Nestle's product isavailable in China, raising concerns the Swiss group's versioncould eat into a2 Milk Company's market share there.

Following strong cues from their U.S. counterparts, Australian real estate stocks climbed as muchas 1 percent.

Real estate investment trust Dexus firmed 1.6percent, its biggest intraday percentage gain in more thansix-weeks, while Goodman Group, Australia's largestlisted property owner, rose 0.8 percent.

Across the Tasman sea, New Zealand's benchmark S&P/NZX 50index fell 0.6 percent or 50.85 points to 8,337.23, itwas on track to lose 0.4 percent for the month.

a2 Milk Company fell 4.6 percent to an overfive-week low, accounting for about half of the losses on thebenchmark.

(Reporting by Aditya Soni in Bengaluru; Editing by Sam Holmes)