Message : Required fields (Reuters) -Canada's main stock index opened higher on Thursday as investors bet on a faster global economic rebound, while a jump in gold and copper prices helped mining stocks. The materials sector, which includes precious and base metals miners and fertilizer companies, added 1.3% as gold futures rose 0.5% to $1,748.7 an ounce to hit a three-week peak. [GOL/] [METL/] * At 9:37 a.m. ET (13:37 GMT), the Toronto Stock Exchange's S&P/TSX composite index was up 8.37 points, or 0.04%, at 19,137.44. * Canada's Canopy Growth Corp said on Thursday it will buy rival Supreme Cannabis Co Inc for C$323.3 million ($256.85 million), as the world's biggest cannabis producer bolsters its portfolio to tap surging demand.