June 9 (Reuters) - Canada’s main stock index opened lower on Wednesday as financial stocks declined ahead of the central bank’s interest rate decision, while Dollarama Inc fell due to a downbeat forecast. * At 9:30 a.m. ET (1330 GMT), the Toronto Stock Exchange’s S&P/TSX composite index was down 37.53 points, or 0.19%, at 20,028.39, with the financials sector slipping 0.4%. * Dollarama Inc fell 2.5% and was among the top decliners on the main index after the company said its current-quarter earnings would take a hit from fresh COVID-19 restrictions in certain Canadian provinces. (Reporting by Shreyashi Sanyal in Bengaluru; Editing by Aditya Soni) Our Standards: The Thomson Reuters Trust Principles.