The Nasdaq 100 index finished lower on Monday, as investors mulled record-high crude oil prices and shares of Sirius Satellite Radio Inc. posted declines.
Light, sweet crude for August delivery hit a record $143.67.
The index, which includes 100 of the largest nonfinancial securities listed on the Nasdaq Stock Market, declined 18.63 points, or 1 percent, to 1,837.09, while the broader Nasdaq composite declined 22.65 points to 2,292.98.
Shares of Sirius Satellite Radio fell 18 cents, or 8.6 percent, to $1.92. The company said it expects to save $400 million in 2009 through its proposed takeover of XM Satellite Radio Holding Inc.
Shares of Apollo Group Inc. declined $3.69, or 7.7 percent, to $44.26, ahead of the for-profit education company's quarterly report on Tuesday.
Shares of UAL Corp., which operates United Airlines, declined 34 cents, or 6.1 percent, to $5.22, a 52-week low. Fuel is one of an airline's biggest costs.
On the rising side, shares of Ryanair Holdings PLC added $1.47, or 5.4 percent, to $28.67.
Shares of Vertex Pharmaceuticals Inc. rose 97 cents, or 3 percent, to $33.47.
KLA-Tencor Corp.'s stock rose $1, or 2.5 percent, to $40.71. The maker of chip manufacturing equipment authorized the repurchase of 15 million shares.