* Canadian dollar falls 0.3% against the greenback * Loonie trades in a range of 1.2287 to 1.2340 * Price of U.S. oil falls 0.5% * Canadian bond yields ease across a flatter curve TORONTO, June 28 (Reuters) - The Canadian dollar weakened against its U.S. counterpart on Monday as investors weighed rising coronavirus cases in Australia and Asia, with the currency giving back some of last week"s advance. Global shares and oil, one of Canada"s major exports, edged lower as Sydney plunged into a lockdown after a cluster of cases involving the highly contagious Delta strain ballooned. U.S. crude oil futures fell 0.5% to $73.71 a barrel, while the Canadian dollar was trading 0.3% lower at 1.2334 to the greenback, or 81.08 U.S. cents. The currency traded in a range of 1.2287 to 1.2340. Last week, the loonie advanced 1.4% as investors grew less worried about the recent hawkish shift from the Federal Reserve. Still, speculators have cut their bullish bets on the Canadian dollar for a third week, data from the U.S. Commodity Futures Trading Commission showed on Friday. As of June 22, net long positions had fallen to 43,225 contracts from 44,254 in the prior week. Canada"s GDP report for April is due on Tuesday which could offer clues on the strength of the economy. Investors are also awaiting U.S. payrolls data and an OPEC+ meeting later in the week. Canadian government bond yields were lower across a flatter curve, tracking the move in U.S. Treasuries. The 10-year eased 2.8 basis points to 1.431%. (Reporting by Fergal Smith; Editing by Kirsten Donovan) Our Standards: The Thomson Reuters Trust Principles.