LONDON, Oct 24 (Reuters) - Portugal's 10-year government bond yield fell sharply on Monday to its lowest level in just over six weeks, after ratings agency DBRS confirmed the country's remaining investment grade rating that is key for inclusion in the ECB's bond buying scheme.

DBRS maintained its BBB (low) investment grade rating with a stable outlook after the close of markets on Friday, citing Portugal's progress in reducing its budget deficit.

Portuguese bond yields, which fell on Friday as investors anticipated the country would keep the investment grade rating, fell further as markets opened on Monday.

Portugal's 10-year bond yield was down 9 basis points at 3.11 percent, its lowest level since Sept. 9. Other euro zone bond yields were 2-3 bps lower on the day.

(Reporting by Dhara Ranasinghe; Editing by Andrew Heavens)