TORONTO (Reuters) - The Toronto Stock Exchange's main index ended flat after a warning by the US Federal Reserve led to a flurry of volatility but no overall direction.

The S&P/TSX composite index closed down 4.67 points, or 0.03 percent, at 13,560.57. Earlier in the session, it was down more than 100 points to lows not visited since early May, before rebounding sharply to an intraday high of 13,627.94.

Six of the TSX index's 10 main groups ended lower in the see-saw session, led by a 1.6 percent drop in the influential energy group and a 0.9 percent retreat by telecoms. Financials led the upside, gaining 1.4 percent.

All eyes were on the Federal Reserve, which held US interest rates steady but warned that households and businesses could be facing tightening credit conditions.

North American markets, which were braced for news on how the US subprime crisis would affect economic growth, fell sharply on the prospect of rate hikes that could curb consumer spending and hurt corporate profits.

But the TSX benchmark, along with other major indexes, quickly regained most of those losses late in the day, partly because the Fed said it still saw moderate economic growth ahead.

"Sometimes the big players try to push the market one way or another to see where the offerings really are and sometimes that creates a vacuum, so (the index) just ricocheted right back up," said Bruce Latimer, a trader at Dundee Securities in Toronto.

"If you're going to have huge amounts of volatility on the US market, that's going to follow through on the Canadian market."

Energy producers represented the three biggest weighted losers yesterday. EnCana was down C$1.26, or nearly 2 percent, at C$63.24, and Talisman Energy was off 60 Canadian cents, or 3.2 percent, at C$18. Canadian Natural Resources slipped 93 Canadian cents, or 1.3 percent, to C$69.91.

Their slide came despite higher US crude and natural gas prices. Most metals prices also gained, but the TSX materials sector declined 0.1 percent.

Financial shares were led higher by Manulife Financial , which climbed C$1.08, or 2.8 percent, to C$39.74. Brookfield Asset Management was up C$2.44, or 7.2 percent, at C$36.46.