CANADA STOCKS-TSX drops as COVID-19 cases rise; oil weighs

(Adds trading details)

Sept 21 (Reuters) - Canada’s main stock index fell on Monday as an increase in COVID-19 cases raised fears of a second round of lockdowns, while oil prices fell on the possible return of Libyan oil production.

* Canada’s most populous province is cracking down on private social gatherings as COVID-19 cases surge, Ontario Premier Doug Ford said in a surprise news conference called on Saturday.

* At 9:50 a.m. ET (1350 GMT), the Toronto Stock Exchange’s S&P/TSX composite index was down 291.94 points, or 1.8%, at 15,907.03.

* Canadian pipeline operator TC Energy Corp said on Monday Chief Operating Officer François Poirier will take over as its president and chief executive officer after current boss Russ Girling retires at the end of this year. Its shares were down 2.6% in early trading.

* The energy sector dropped 4.1% as U.S. crude prices were down 2.8% a barrel, while Brent crude lost 2.6%.

* The materials sector, which includes precious and base metals miners and fertilizer companies, lost 1.6% as gold futures fell 1.9% to $1,916 an ounce.

* On the TSX, five issues were higher, while 216 issues declined for a 43.20-to-1 ratio to the downside, with 32.32 million shares traded.

* The largest percentage gainers on the TSX were Shopify Inc and Cominar REIT, rising 1.7% and 0.6%, respectively.

* Vermilion Energy Inc fell 7.2%, the most on the TSX, while the second-biggest decliner was MEG Energy Corp , down 6.7%.

* The most heavily traded shares by volume were Baytex Energy Corp, New Millennium Iron Corp and Bombardier Inc.

* The TSX posted no new 52-week high or low.

* Across all Canadian issues, there were four new 52-week highs and 10 new lows, with total volume of 65.54 million shares. (Reporting by Shashank Nayar in Bengaluru; Editing by Maju Samuel)