April 18 (Reuters) - Canada's main stock index rose on Monday as higher commodity prices bolstered the energy and materials sectors, although concerns around rising U.S. bond yields kept sentiment in check.

At 9:39 a.m. ET (13:39 GMT), the Toronto Stock Exchange's S&P/TSX composite index was up 54.39 points, or 0.25%, at 21,910.09.

Meanwhile, U.S. stocks inched lower at open as Treasury yields continued to rise on expectations of a tighter monetary policy.

"Markets are a little bit soft and that's around the world, not specific to Canada. The one thing that helped Canada is climbing commodity prices," said Colin Cieszynski, chief market strategist at SIA Wealth Management.

The energy sector was up 1.2%, supported by higher oil prices as outages in Libya deepened concern over tight global supply and the Ukraine crisis dragged on.

The materials sector, which includes precious and base metals miners and fertilizer companies, added 1.1% as gold prices jumped to a more than one-month high over the economic fallout from the Russia-Ukraine war and surging inflation.

"Gold once again is approaching $2,000/oz... suggesting some investors are positioning defensively," Cieszynski added.

While most stock markets are rattled with a surge in inflation and a possible economic slowdown, the TSX hit a record high earlier this month supported by surging commodity prices.

Among the sectors that lost ground was technology, down 1.4%, tracking weakness in the U.S. tech-heavy Nasdaq index.

While healthcare shed 2.2% with pot producers including Canopy Growth, Tilray Brands, and Aurora Cannabis among the top decliners.

HIGHLIGHTS

The TSX posted 26 new 52-week highs and two new lows.

Across all Canadian issues there were 68 new 52-week highs and 38 new lows, with total volume of 28.99 million shares. (Reporting by Amal S in Bengaluru; Editing by Shailesh Kuber)