Aug 28 (Reuters) - Canada's main stock index dipped on Tuesday as losses in the healthcare sector led by marijuana companies overshadowed gains in precious metal miners as gold prices edged higher.
* Cannabis producers Canopy Growth WEED.TO , Aurora Cannabis ACB.TO and Aphria APH.TO fell between 6 percent and 8 percent and were the biggest decliners on the main index.
* Also weighing was the heavyweight financial sector's 0.3 percent fall, led by Canada's third-biggest lender Bank of Nova Scotia BNS.TO , which reported third-quarter earnings in line with market expectations. However, rival Bank of Montreal BMO.TO rose 0.3 percent after topping third-quarter earnings estimates, helped by growth in the United States.
* Only three of the index's 11 major sectors were higher, led by the material sector's .GSPTTMT 0.6 percent rise.
* Gold edged higher, helped by weakness in the dollar but analysts said ongoing U.S.-China tensions would continue to weigh.
* Investors expect Canada would agree to new terms to preserve a three-nation pact after the United States and Mexico reached a deal to overhaul the North American Free Trade Agreement. At 9:54 a.m. ET (13:54 GMT), the Toronto Stock Exchange's S&P/TSX composite index .GSPTSE was down 31.65 points, or 0.19 percent, at 16,412.74.
* On the TSX, 101 issues were higher, while 135 issues declined for a 1.34-to-1 ratio to the downside, with 30.42 million shares traded.
* The largest percentage gainers on the TSX were shares of Canadian auto-part makers Linamar Corp LNR.TO , which jumped 4.7 percent and Martinrea International MRE.TO , which rose 3.9 percent.
* The most heavily traded shares by volume were Aurora Cannabis ACB.TO , Aphria Inc APH.TO and Canopy Growth Co.
* The TSX posted four new 52-week highs and one new low.
* Across all Canadian issues there were 19 new 52-week highs and 8 new lows, with total volume of 50.34 million shares.