By Swati Pandey and Charlotte Greenfield
SYDNEY/WELLINGTON, June 21 (Reuters) - The Australian dollar fell for a third straight session to a one-week trough on Wednesday as oil prices tumbled, while its New Zealand counterpart weakened after a disappointing dairy auction.
The Australian dollar AUD=D4 slipped 0.2 percent to $0.7563, a level not seen since June 14. It last traded at $0.7571. The Aussie has failed repeatedly to sustain a breach of chart resistance above $0.7630 after touching a 10-week high of $0.7636 last week.
"The Aussie dollar is looking vulnerable this morning due to the combined impact of the collapse in oil prices and the drop in U.S. markets," said Greg McKenna, chief market strategist at AxiTrader.
Technical analysts say the Aussie may slip to $0.7515/20 if it fails at current levels. It is up 5.2 percent so far this year, putting it among the best performing major currencies.
Oil fell about 2 percent on Tuesday, with Brent settling at seven-month lows, led by increased supply from several key producers. O/R
The New Zealand dollar NZD=D4 edged down to $0.7232 from $0.7268, drifting away from four-month highs of $0.7320 touched last week.
Prices for milk products, the country's largest goods export, fell 0.8 percent despite market expectations of a gain. next big event for the currency is the Reserve Bank of New Zealand (RBNZ) rate decision on Thursday, in which the central bank is all but certain to keep rates on hold.
Some analysts suspect the RBNZ will protest the strength of the local currency. New Zealand dollar "is expected to remain fairly stable ahead of tomorrow's RBNZ announcement," said Con Williams, ANZ economist, in a research note. "Given the recent strength, the NZD is likely to be a focal point for the RBNZ tomorrow morning."
New Zealand government bonds 0#NZTSY= gained, sending yields one basis point lower along the curve.
Australian government bond futures rose, with the three-year bond contract YTTc1 up 1 tick at 98.170. The 10-year contract YTCc1 edged 1.5 ticks higher to 97.555. (Editing by Jacqueline Wong)