TORONTO, Oct 29 (Reuters) - The Canadian dollar strengthened to a six-week high against its US counterpart on Thursday after the start of a Bank of Canada tightening cycle helped narrow the gap between Canadian and US bond yields. The loonie was trading 0.1% higher at 1.3982 per US dollar, or 71.52 US cents, after touching its strongest intraday level since September 16 at 1.3966. * The gap between Canada's 2-year yield and the US equivalent narrowed by 4.7 basis points to about 128 basis points in favor of the US note.