May 31 (Reuters) - Canada's main stock index fell on Friday, as energy shares were hit by a more than 2% drop in oil prices following U.S. President Donald Trump's shock threat of tariffs on Mexico.
* At 9:40 a.m. ET (13:40 GMT), the Toronto Stock Exchange's S&P/TSX composite index .GSPTSE was down 118.53 points, or 0.74%, at 15,970.71, on track for its first monthly decline this year.
* Trump's directive also spelled the potential for chaos for the U.S. Congress approval of USMCA deal, which was negotiated as a replacement to the North American Free Trade Agreement between the United States, Mexico and Canada. Meanwhile, latest data showed the Canadian economy grew slower than expected in the first quarter, although market participants were heartened by signs of a strong recovery in March. Ten of the index's 11 major sectors were lower, dragged down by a 1.7% fall in the energy sector .SPTTEN .
* U.S. crude CLc1 prices were down 2.8% a barrel, while Brent crude LCOc1 lost 3.0%, tracking their biggest monthly drop in six months. O/R
* The heavyweight financials sector .SPTTFS slipped 1.2% and the industrials sector .GSPTTIN shed 0.8%.
* Among notable gainers was the materials sector .GSPTTMT . The sector, which includes precious and base metals miners and fertilizer companies, added 1.6%.
* The largest percentage gainers on the TSX were Yamana Gold Inc YRI.TO and Iamgold Corp IMG.TO , which rose 5.6% and 4.7%, respectively.
* Investors' flight to safer assets boosted gold prices. Gold futures GCc1 rose 0.8% to $1,297.9 an ounce. GOL/ MET/L
* On the TSX, 46 issues were higher, while 194 issues declined for a 4.22-to-1 ratio to the downside, with 18.64 million shares traded.
* BRP Inc DOO.TO fell 5.7%, the most on the TSX, while the second-biggest decliner was Nuvista Energy NVA.TO , down 5.0%.
* The most heavily traded shares by volume were Avalon Advanced Materials AVL.TO , Aurora Cannabis Inc ACB.TO and First Quantum Minerals FM.TO .
* The TSX posted two new 52-week highs and ten new lows.
* Across all Canadian issues, there were 27 new 52-week highs and 26 new lows, with total volume of 33.10 million shares.