April 21 (Reuters) - Canada's main stock index fell on Tuesday, dragged down by a sell-off in the heavyweight energy sector after U.S. oil futures sank into negative territory.
* * At 9:49 a.m. ET (1349 GMT), the Toronto Stock Exchange's S&P/TSX composite index .GSPTSE was down 139.3 points, or 0.97%, at 14,248.98.
* The energy sector .SPTTEN dropped 2.2%, extending losses into a second straight session.
* Benchmark Brent and U.S. oil futures for June delivery plunged to around two-decade lows on Tuesday, a day after U.S. May futures sank into negative territory for the first time in history as demand tumbled due to the coronavirus crisis. O/R
* The materials sector .GSPTTMT , which includes precious and base metals miners and fertilizer companies, lost 2.1% due to lower gold and base metal prices as investors made a dash for the U.S. dollar. GOL/ MET/L
* On the TSX, 11 issues were higher, while 219 issues declined for a 19.91-to-1 ratio to the downside, with 25.30 million shares traded.
* Oil and gas explorer Seven Generation VII.TO fell 7%, the most on the TSX, while the second-biggest decliner was Linamar Corp LNR.TO , down 4.5%.
* The best performer on the TSX was ecommerce firm Shopify Inc SHOP.TO , which extended gains into a third straight session as coronavirus-driven lockdowns boost online traffic.
* The most heavily traded shares by volume were Royal Bank of Canada RY.TO and Bombardier BBDb.TO .
* The TSX posted 2 new 52-week highs and no new lows.
* Across all Canadian issues there were 9 new 52-week highs and 3 new lows, with total volume of 48.35 million shares.