June 2 (Reuters) - Canada’s main stock index opened at a record high on Wednesday, driven by gains in energy stocks as an OPEC+ decision to gradually restore crude supply lifted oil prices. * At 9:32 a.m. ET (13:32 GMT), the Toronto Stock Exchange’s S&P/TSX composite index was up 45.57 points, or 0.23%, at 20,021.58. Reporting by Shivani Kumaresan in Bengaluru; Editing by Aditya Soni Our Standards: The Thomson Reuters Trust Principles.