* Aussie shares post biggest weekly decline since March
* Materials and energy stocks biggest drags
* a2 Milk rally drives NZ higher (Updates to close)
May 25 (Reuters) - Australian shares edged down on Friday, as declines in materials and energy stocks on lower commodities and oil prices outweighed gains in consumer staples and consumer discretionary stocks.
The S&P/ASX 200 index slipped 0.1 percent or 4.3 points to 6,032.8 at the close of trade. The benchmark rose 0.1 percent on Thursday and fell 0.9 percent for the week, its biggest decline since March.
Materials accounted for most of the losses, with global miner BHP slipping 2.5 percent, its biggest in more than two-months, while rival Rio Tinto Ltd fell 0.9 percent.
BHP, which owns shale assets in the U.S., was also hurt by a fall in oil prices, making it the biggest drag on the main index.
Oil prices eased on Friday putting energy stocks under the cosh. Woodside Petroleum Ltd declined 2.2 to a more than two-week low, while Origin Energy Ltd slipped 0.9 percent to its lowest since May 15.
Elsewhere, consumer staples led the gainers, with conglomerate Wesfarmers Ltd rising 0.9 percent to its highest since Feb. 2015, while Treasury Wine Estates Ltd jumped 3.7 percent.
Consumer discretionary stocks also accumulated profits, with Aristocrat Leisure Ltd surging 4.3 percent to its highest ever level.
Meanwhile, New Zealand’s benchmark S&P/NZX 50 index rose 0.6 percent or 47.63 points to finish the session at 8,638.40 and registered a weekly decline of 0.2 percent.
Consumer staples led the gains, with dairy firm a2 Milk Company Ltd rising 2.6 percent, boosting the main index, while Synlait Milk Ltd climbed 2.2 percent, its biggest one day gain in more than one-week. (Reporting by Aditya Soni in Bengaluru; Additional reporting by Shanima A; Editing by Sam Holmes)