(Updates prices, sectors) June 18 (Reuters) - Canada’s main stock index was set to mark its worst day in more than two weeks on Friday, dragged by energy stocks as oil prices dropped for a second straight day on the prospect of interest rate hikes in the United States. * The energy sector fell 1.1% as U.S. crude prices were down 0.4% a barrel, while Brent crude lost 0.6%. * At 9:39 a.m. ET (1339 GMT), the Toronto Stock Exchange’s S&P/TSX composite index was down 122.7 points, or 0.61%, at 20,021.34. * Marine port service provider Westshore Terminals Investment Corp fell 4.9%, the most on the TSX, and the second-biggest decliner was apparel maker Gildan Activewear Inc , down 2.2%. * The financials sector slipped 0.9%. The industrials sector fell 0.7%. * Meanwhile, the materials sector, which includes precious and base metals miners, and fertilizer companies, lost 0.2%. * On the TSX, 53 issues were higher, while 166 issues declined for a 3.13-to-1 ratio to the downside, with 88.85 million shares traded. * The largest percentage gainers on the TSX were cybersecurity firm BlackBerry Ltd, which jumped 2.2%, extending its rally amid the “meme-stock” frenzy and e-commerce firm Shopify Inc, which rose 1.9%. * The most heavily traded shares by volume were Toronto-Dominion Bank, Royal Bank of Canada and Bank of Nova Scotia. * The TSX posted four new 52-week highs and no new lows. * Across all Canadian issues there were 14 new 52-week highs and five new lows, with a total volume of 104.00 million shares. (Reporting by Amal S in Bengaluru; Editing by Ramakrishnan M.) Our Standards: The Thomson Reuters Trust Principles.