* The Toronto Stock Exchange's TSX falls 0.85 percent to 19,040.78
* Leading the index were OceanaGold Corp , up 5.0%, B2Gold Corp, up 3.5%, and Osisko Mining Inc, higher by 3.4%.
* Lagging shares were OrganiGram Holdings Inc, down 10.1%, Aphria Inc, down 8.6%, and Whitecap Resources Inc, lower by 6.5%.
* On the TSX 114 issues rose and 111 fell as a 1-to-1 ratio favored advancers. There were 19 new highs and 1 new low, with total volume of 198.0 million shares.
* The most heavily traded shares by volume were Whitecap Resources Inc, Air Canada and Suncor Energy Inc.
* The TSX's energy group fell 4.65 points, or 4.0%, while the financials sector slipped 3.49 points, or 1.0%.
* West Texas Intermediate crude futures fell 1.21%, or $0.77, to $62.61 a barrel. Brent crude fell 1.16%, or $0.78, to $66.27.
* The TSX is up 9.2% for the year.
This summary was machine generated April 20 at 21:03 GMT.