OTTAWA (Reuters) - The Bank of Canada once again predicted on Wednesday a delayed return to desired economic growth rates, but it left interest rates unchanged and repeated that at some point it would probably tighten monetary policy. "With continued slack in the Canadian economy, the muted outlook for inflation, and the constructive evolution of imbalances in the household sector, the considerable monetary policy stimulus currently in place will likely remain appropriate for a period of time, after which some modest withdrawal will likely be required...," the central bank stated. ...