TORONTO (Reuters) - Toronto's main stock index ended lower yesterday after the US Federal Reserve signalled it was concerned about slowing growth and felt it should stand ready to consider additional steps to boost the US economy if the outlook worsened.

Minutes from the US central bank's June 22-23 policy meeting, along with disappointing US retail sales figures for June, shifted the balance of sentiment into negative territory.

Earlier, the TSX was little changed with firm oil prices and healthy US earnings offsetting the retail data.

"A lot of noise is in the marketplace. You just sort of have to work through. Ultimately it's going to be day-by-day on how the market reacts to any kind of news," said Brian Pow, vice-president, research and equity analyst at Acumen Capital Partners, in Calgary.

Volumes are also growing thinner, reflecting the onset of summer trading, Pow said, and that is likely to exaggerate market moves.

"Generally speaking, I think the volumes are going to be a little bit lighter and a little less indicative of what's going on in the underlying economy," said Mr. Pow.

The Toronto Stock Exchange's S&P/TSX composite index ended down 52.68 points, or 0.45 percent, at 11,620.16. Nine of its 10 main sectors were lower, including the energy group, down 0.69 percent.

US crude oil futures, which had a volatile session, turned negative yesterday afternoon after the Fed's minutes, settling near $77 a barrel.

Suncor Energy was off 1.05 percent at C$32.83, while Husky Energy fell 1.89 percent to C$26.43.

The TSX's financial group, often a play on the broader economy, was 0.47 percent lower, with Royal Bank of Canada down 0.58 percent at C$54.56 and Toronto-Dominion Bank off 0.59 percent at C$72.12.

Bank of Montreal bucked the trend, rising 0.57 percent to C$61.42.

Early support for the broader market came from robust quarterly results posted by Intel Corp., which sent positive signals across the cyclical technology industry and prompted at least four brokerages to raise their share price targets for the world's largest chipmaker.