(Corrects to show DH Corp fell ahead of, not after, earnings report in final paragraph)

* TSX ends down 162.76 points, or 1.17 percent, at 13,790.90

* Nine of index's 10 main groups fall

By Alastair Sharp

TORONTO, Oct 26 (Reuters) - Canada's main stock index fell on Monday as resources stocks weighed and investors remained skittish about Valeant Pharmaceuticals despite its attempts to address recent allegations made against it by an influential short-seller.

Nine of the index's 10 main groups fell, led by a 5 percent retreat for the heavyweight energy group, a 4 percent loss for materials stocks, and a 5.2 percent drop in consumer staples.

The losses among resource stocks were much sharper than any slips in prices for the underlying commodities they extract, refine or transport.

"The month has been marked by this very strong move on very little information, and the market is now digesting it and saying 'there's not a lot here'," said John Stephenson, president at Stephenson & Company Capital Management.

The most influential single weight was Valeant, down 4.8 percent at C$145.34, after it laid out a detailed defense of its relationship with a specialty pharmacy that failed to calm all investor concerns.

"The nagging sense is why are we hearing about this at the last minute and given that we're hearing about it at the last minute, what else aren't they telling us," Stephenson said.

The most influential movers in the energy group were pipeline operator Enbridge Inc, down 2.2 percent at C$55.63, and Canadian Natural Resources, which declined 2.5 percent to C$30.32.

U.S. crude prices settled down 1.4 percent at $43.98 a barrel, while Brent crude lost 1.2 percent to $47.42.

Gold miners were also among the weights even as bullion steadied after a three-day losing streak, with Goldcorp Inc declining 4 percent to C$19.66 and Barrick Gold Corp falling 3.2 percent to C$9.88.