* TSX tumbles 317.61 points, or 2.61 percent, to 11,844.56
* Cut to U.S. AAA rate shakes investor confidence
* All 10 sectors lower, led by oil and gas
* Index pares some losses, helped by gold stocks (Adds details)
By Ka Yan Ng
TORONTO, Aug 8 (Reuters) - Toronto's main stock market index hit its lowest point in nearly a year on Monday as Standard & Poor's cut to the top-tier AAA credit rating of the United States shook investor confidence, knocking commodity prices lower.
The move tracked world stocks, which tumbled on deep-rooted jitters about the U.S. debt rating cut, overshadowing relief that the European Central Bank was buying bonds of euro zone strugglers Italy and Spain. [MKTS/GLOB]
"That's really what has energized this move on the downside. We've sauntered around all year basically on the weaker side, and this has only emphasized that," said Fred Ketchen, director of equity trading at ScotiaMcLeod.
"And in fact, it has put the downside a whole lot more in focus."
The index had tumbled more than 3 percent shortly after the open to 11,769.40, its lowest since Aug. 27, 2010. The index has ended lower in seven of the last nine sessions.
By 10:07 a.m. (1407 GMT), the resource-heavy Toronto Stock Exchange's S&P/TSX composite index .GSPTSE had pared some losses, and was down 317.61 points, or 2.61 percent, at 11,844.56. All 10 main sectors were on the decline.
The weakness was sharpest in the oil and gas sector, which was down 4.6 percent and followed the price of oil lower. Crude dropped close to 4 percent and was under $84 a barrel as concern over economic growth spread. [O/R]
Top decliners were Suncor Energy (SU.TO), down 4.6 percent at C$30.84, while Canadian Natural Resources (CNQ.TO) was off 4.2 percent at C$33.75.
Economically-sensitive financial stocks were also steep decliners, with Toronto-Dominion Bank (TD.TO) down 2.7 percent at C$71.89, and Royal Bank of Canada (RY.TO) shedding 2.4 percent to C$48.86.
But gold-miners were seen as a relative safe-haven investment, with the price of bullion vaulting to a record over $1,700 an ounce. [GOL/] (Editing by Jeffrey Hodgson)