• AUD/USD hits 0.6446 after extending south from 0.6537 (six-month top Monday)

• Drop to 0.6446 influenced by USD buy-backs (USD index hit 5-week low Monday)

• 0.6495 was Asia high. U.S. consumer confidence gauge due at 1400 GMT; 87 f/c

• Australia April inflation data due at 0130 GMT; CPI forecast at 2.3% YY

• CFTC data: net AUD short rose 20% to six-week high of 59k in week to May 20

• Weak Chinese demand leaves Australia with too much wheat

AUDUSD

(Robert Howard is a Reuters market analyst. The views expressed are his own)