TORONTO (Reuters) - Canada's main stock index fell on Thursday, hurt by sharp selloffs in Goldcorp Inc (>> Goldcorp Inc.) and SNC-Lavalin Group Inc (>> SNC-Lavalin Group Inc).

Goldcorp, the world's biggest gold producer by market value, posted a hefty loss as it took a $2.3 billion impairment charge on a new mine in Argentina, the second multibillion-dollar writedown from a top gold miner in as many days.

The stock tumbled 7.9 percent to C$26.65, dragging the gold-mining sector down 2 percent.

Shares of SNC-Lavalin Group (>> SNC-Lavalin Group Inc) tumbled 7.1 percent to C$40.63 after Canadian police laid corruption charges against the company and some of its units in relation to their operations in Libya.

The Toronto Stock Exchange's S&P/TSX composite index <.GSPTSE> ended down 32.42 points, or 0.21 percent, at 15,180.33. Six of the 10 main sectors on the index retreated.

Oil prices have remained under pressure since Wednesday, following a strong rebound from multi-year lows hit in January. The crude slump has hit Canada's index hard, given the large number of producers listed here.

"I don’t know if we've found a bottom yet. There's potential to retest lows," said Kevin Headland, director for capital

markets and strategy at Manulife Asset Management.

Crescent Point Energy Co (>> Crescent Point Energy Corp) fell 3.8 percent to C$30.77 and pipeline operator TransCanada Corp (>> TransCanada Corporation) declined 0.7 percent to C$56.16.

Financials, the index's most heavily weighted sector, were lower overall. Royal Bank of Canada (>> Royal Bank of Canada) added 0.6 percent to C$77.23 while Toronto-Dominion Bank slipped 0.3 percent to C$54.45.

(Additional reporting and writing by Alastair Sharp; Editing by Bernadette Baum)

By John Tilak