Midday Leaders and Laggards: Nasdaq 100

The Nasdaq 100 index rallied in midday trading Wednesday after a report showed the service sector rose slightly last month and crude oil prices slipped on demand concerns.

The index, which includes 100 of the largest nonfinancial securities listed on the Nasdaq Stock Market, rose 32.48 points to 2,029.27 in midday trading. Of the index's 100 constituents, only 5 were down.

The broader Nasdaq composite added 32.55 points to 2,513.03.

Shares of Ryanair Holdings PLC, an Irish airline, rose $2.42, or 9 percent, to $29.42.

Shares of United Airlines parent UAL Corp. gained 84 cents, or 9.9 percent, to $9.37. The airline said it will prune 1,100 jobs and shed 70 airplanes from its fleet, slashing domestic capacity as it moves to cope with skyrocketing jet fuel costs.

The profitability of airline operators is closely linked to jet-fuel costs.

Shares of Apollo Group Inc., which runs the University of Phoenix, gained $2.41, or 5.2 percent, to $49.

On the declining side, shares of Vertex Pharmaceuticals Inc. shed 53 cents to $29.

Shares of Marvell Technology Group Ltd. fell 20 cents to $17.10.

Shares of NetApp Inc. slipped 13 cents to $23.83. The network storage company said late Tuesday it plans to sell $1.1 billion in five-year convertible senior notes to institutional buyers.