* TSX ends down 2.1%, at 19,791.62
* Posts its lowest closing level in four weeks
* Materials group falls 2.4%, with Teck Resources down 4.4%
* Technology ends 3.4% lower
Sept 21 (Reuters) - Canada's main stock index posted its biggest decline in one year on Thursday as the U.S. Federal Reserve's hawkish stance added to investor worries that higher borrowing costs will derail economic growth.
The Toronto Stock Exchange's S&P/TSX composite index was down 423.07 points, or 2.1%, at 19,791.62, its lowest closing level since Aug. 24 and its biggest decline since September 2022.
Wall Street also posted big declines, a day after the Fed's projections showed another possible rate hike this year as well as significantly tighter rates through 2024 than previously expected.
"Yields appear to be spiking, so people are still worried about future rate hikes," said Michael Sprung, president at Sprung Investment Management. "Inflation is not tamed yet and I think the market is getting worried about the financial position of consumers."
The Canadian 10-year yield touched a 15-year high at 3.98%. Data on Tuesday showed that Canadian inflation climbed more than expected to 4% in August.
Canada's record of declining productivity over the past three years is likely to make it more difficult for the Bank of Canada to tame inflation, raising the prospect of additional interest rate hikes even as the economy slows.
All 10 of the Toronto market's major sectors lost ground, including a decline of 2.4% for materials, which includes precious and base metals miners and fertilizer companies, as copper and gold prices fell.
Shares of Teck Resources Ltd were among the biggest decliners, falling 4.4%. India's JSW Steel Ltd is slowing down the process to buy a stake in Teck's steelmaking coal unit, a source close to the discussions said, in the first sign that a diplomatic spat is affecting trade ties.
Energy fell 1.5%, technology lost 3.4% and heavily-weighted financials were down 1.8%. (Reporting by Fergal Smith in Toronto and Khushi Singh in Bengaluru; Editing by Tasim Zahid and Marguerita Choy)