* TSX down 70.27 points, or 0.47 percent, at 14,727.56
* Seven of 10 main index sectors decline
* First Quantum, Teck slip with copper prices
By John Tilak
TORONTO, Jan 27 (Reuters) - Canada's main stock index fell sharply on Tuesday, with the market continuing to feel uncertainty fueled by the victory of a left-wing party in Sunday's Greek election and with weaker copper prices pulling mining shares lower.
Copper prices neared their lowest levels in 5-1/2 years on concerns about China's economic growth. That sent shares of miner First Quantum Minerals Ltd tumbling 7.5 percent to C$11.31. Teck Resources Ltd dropped 3.3 percent to C$15.34.
While investors were still processing news that the victorious Syriza party in Greece was making demands for a restructuring of the country's international debt, sluggish U.S. earnings reports, including one from Microsoft Corp on Monday, were also hitting the market.
The benchmark TSX index's fall followed gains in each of the four previous sessions. It is up slightly this year.
"When you put it all together - Greece, Russia, earnings and the other uncertainties - you have a bit of a buyer's boycott," said Irwin Michael, portfolio manager at ABC Funds.
"The sentiment for Canadian stocks is negative," he added. "There's a move towards U.S. securities because most people are confident in the U.S. dollar and feeling better about the U.S. economy."
The Toronto Stock Exchange's S&P/TSX composite index was down 70.27 points, or 0.47 percent, at 14,727.56. Seven of the 10 main sectors on the index were in the red.
Financials, the index's most heavily weighted sector, gave back 0.9 percent. Royal Bank of Canada shed 1.1 percent to C$74.52, and Toronto-Dominion Bank lost 0.9 percent to C$51.95.
Shares of oil and gas producers were down more than 1 percent, reflecting choppiness in oil prices. Canadian Natural Resources Ltd fell 1.8 percent to C$35.61.
$1=$1.24 Canadian Editing by Peter Galloway