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July 3 (Reuters) - Canada's main stock index retreated on Friday as a record surge in COVID-19 cases in the United States raised fears of another round of lockdowns, overshadowing early signs of an economic rebound from the pandemic-driven slump.
* The United States reported more than 55,000 new COVID-19 cases on Thursday, a new daily global record for the pandemic.
* At 9:40 a.m. EDT (1340 GMT), the Toronto Stock Exchange's S&P/TSX composite index was down 23.49 points, or 0.15%, at 15,598.91. With U.S. stock markets closed for a public holiday, trading volumes were lower than usual.
* The index was still on course to close higher on the week after being earlier boosted by data showing a jump in May exports.
* The energy sector dropped 0.3% as U.S. crude and Brent crude lost 1.3%.
* The materials sector, which includes precious and base metals miners and fertilizer companies, lost 0.2% as gold futures were nearly flat.
* On the TSX, 67 issues were higher, while 143 issues declined for a 2.13-to-1 ratio to the downside, with 5.68 million shares traded.
* The largest percentage gainers on the TSX were Ballard Power Systems Inc and BRP Inc, both climbing more than 2%.
* Ero Copper Corp fell 2.3%, the most on the TSX, followed by Real Matters Inc.
* The most heavily traded shares by volume were Nutrien Ltd , Moneta Porcupine Mines Inc and Harte Gold Corp .
* The TSX posted one new 52-week high and no new low.
* Across all Canadian issues, there were 13 new 52-week highs and no new low, with total volume of 13.82 million shares. (Reporting by Sagarika Jaisinghani in Bengaluru Editing by Matthew Lewis and Marguerita Choy)