(Adds strategist quotes and details throughout, updates prices)
* TSX ends down 206.06 points, or 1.1%, at 18,816.80
* Rogers Communications falls 4.6%; Shaw loses 4.3%
* Energy declines 1.4%; oil settles 0.7% lower
* Shopify slides 8.9%
By Fergal Smith
TORONTO, July 11 (Reuters) - Canada's main stock index fell on Monday, giving back gains from the prior week, as a drop in commodity prices weighed on resource shares and concern grew that a major domestic telecom merger was at risk.
The Toronto Stock Exchange's S&P/TSX composite index ended down 206.06 points, or 1.1%, at 18,816.80, after rallying 0.9% last week. Since the start of the year, the index has fallen 11.3%.
"We are seeing a general retrenchment in investor sentiment," said Colin Cieszynski, chief market strategist at SIA Wealth Management. "The rebounds that we saw last week have run out of gas."
U.S. stocks also lost ground as a lack of catalysts left market participants warily embarking on a week back-end loaded with crucial inflation data and the unofficial beginning to second-quarter earnings season.
Central banks worldwide are battling inflation even as the threat of a recession grows. The Bank of Canada is expected to hike by three-quarters of a percentage point on Wednesday.
"There is a lot of news coming but we are in between it all right now ... People are worried enough about what might be coming to be trimming back on stocks at the moment," Cieszynski said.
Shares of Rogers Communications Inc fell 4.6% as analysts voiced concerns over increased risk to the Canadian telecom operator's C$20 billion ($15.4 billion) deal for rival Shaw Communications following last week's 19-hour outage.
Shaw's shares ended 4.3% lower.
Energy shares declined 1.4% as oil prices fell. U.S. crude oil futures settled 0.7% lower at $104.09 a barrel, pressured by an expected drop in demand due to mass testing for COVID-19 in China.
The materials group, which includes precious and base metals miners and fertilizer companies, was also down 1.4%, while technology lost 3.9%, with e-commerce giant Shopify Inc down 8.9%. (Reporting by Fergal Smith; Additional reporting by Bansari Mayur Kamdar in Bengaluru; Editing by Sam Holmes)