Midday Leaders and Laggards: Nasdaq 100

The Nasdaq 100 index declined in midday trading, pulled lower by a rebound in the price of oil and a downgrade of Microchip Technology Inc.

Microchip's stock declined $2.64, or 7.7 percent, to $31.55, following an analyst downgrade from JPMorgan, forecasting a slowdown in the Chinese market.

Elsewhere, Amylin Pharmaceuticals Inc. slipped $1.53, or 5.6 percent, to $26.20, helping reverse gains recorded on Tuesday.

UAL Corp., which operates United Airlines, slipped 32 cents, or 3.9 percent, to $7.93, as the price of oil rose surged above $134 a barrel on the New York Mercantile Exchange.

With only nine stocks rising, the index that includes 100 of the largest nonfinancial securities listed on the Nasdaq Stock Market shed 23.86 points, or 1.2 percent, to 1,948.68. The broader Nasdaq composite declined 26.62 points, or 1.1 percent, to 2,422.32.

On the rising side, shares of Staples Inc. gained $1.20, or 5.2 percent, to $24.37. On Wednesday, Dutch office supplies distributor Corporate Express NV agreed to be bought by the company for $2.7 billion.

An analyst upgrade lifted shares of Petsmart Inc., up 84 cents, or 3.8 percent, to $23.01.

Wynn Resorts Ltd. gained 92 cents to $88.88.