Dec 22 (Reuters) - Canada"s main stock index edged lower on Wednesday in volatile trading, as investors remained cautious amid renewed global restrictions to curb the spread of the Omicron variant, with pot producers leading the losses. At 9:51 a.m. ET (14:51 GMT), the Toronto Stock Exchange"s S&P/TSX composite index (.GSPTSE) was down 33.68 points, or 0.16%, at 20,891.19 a day after reporting its biggest gain since February. Leading losses were the healthcare stocks (.GSPTTHC), down 1.1%, weighed by pot producers Canopy Growth Corp (WEED.TO), Cronos Group Inc (CRON.TO) and Aurora Cannabis Inc (ACB.TO), which were all down over 2%. "Seemed like yesterday was more of a relief rally or a dead cat bounce and today we"re just quiet again. A lot of people are already away on holidays and we"re still getting some lingering tax-loss selling as well," said Colin Cieszynski, chief market strategist at SIA Wealth Management. The energy sector (.SPTTEN) dropped 1.1% even though U.S. crude prices were up 0.1% a barrel. Limiting further losses, however, were the technology stocks that rose 0.4%, with a 16% jump in Dye & Durham Ltd (DND.TO) after the IT service provider said on Tuesday it will acquire Australia-listed Link Administration Holdings Ltd (LNK.AX) for about C$3.2 billion ($2.48 billion). read more Markets have been volatile this month as rising infections due to the Omicron variant of the coronavirus have forced countries to reinstate restrictions and refueled concerns about a slowdown in global economic recovery. The materials sector (.GSPTTMT), which includes precious and base metals miners and fertilizer companies, lost 0.5%. HIGHLIGHTS Blackberry Ltd (BB.TO) fell 5.3%, the most on the TSX, despite the cybersecurity company beating estimates for the third-quarter revenue. The TSX posted two new 52-week highs and no new low. Across all Canadian issues, there were eight new 52-week highs and four new lows, with total volume of 33.14 million shares.