Midday Leaders & Laggards: S&P 500

Shares of Bank of New York Mellon declined $1.30, or 2.7 percent, to $46.18.

Bear Stearns fell $4.13, or 3.6 percent, to $112.04, following many investment banks lower after Merrill Lynch & Co. reported a larger-than-expected third-quarter loss.

The S&P 500 fell 20.74 points to 1,498.85 points in midday trading. The Dow Jones industrial average and the Nasdaq Composite index moved lower, after Merrill's severe credit-related loss.

Adhesive label maker Avery Dennison Corp. said third-quarter earnings fell 31 percent, hurt by charges related to an acquisition and weak U.S. retail demand. The stock fell $1.91, or 3.3 percent, to $57.35.

On the rising side, QLogic Corp. gained $1.40, or 10.4 percent, to $14.88. The data storage and networking devices maker reported adjusted profit and sales above Wall Street expectations.

Paccar Inc. rose $4.77, or 9.5 percent, to $55.15, after the company raised its dividend and reported third-quarter results above Wall Street expectations.

Snap-on Inc.'s stock gained $3.18, or 6.7 percent, to $50.49. The maker of auto repair equipment said quarterly earnings rose on robust sales of its auto diagnostic systems in North America and abroad.