Australia's share market has closed lower amid warnings the economy could be slowing down. (Paul Braven/AAP PHOTOS)Australia's share market has closed lower amid warnings the economy could be slowing down. (Paul Braven/AAP PHOTOS) Credit: AAPAustralian shares have retreated from near all-time highs, after solid earnings from the Commonwealth Bank couldn't allay broader economic fears. The ongoing US-Iran stalemate also weighed on sentiment as oil prices clung to recent gains after fresh attacks on shipping vessels overnight. The Australian dollar is buying 70.61 US cents, up slightly from 70.52 US cents on Tuesday at 5pm.