The orbital character, orientation, and magnetic polarization of the O-2p unoccupied states near the Fermi level (E{sub F}) in CrO{sub 2} was determined using polarization-dependent x-ray absorption spectroscopy and x-ray magnetic circular dichroism from high-quality, single-crystal films. A sharp peak observed just above E{sub F} is excited only by the electric-field vector (E) normal to the tetragonal c axis, characteristic of a narrow band ({approx_equal}0.7 eV bandwidth) constituted from O-2p orbitals perpendicular to c (O-2p{sub y}) hybridized with Cr 3d{sub xz-yz} t{sub 2g} states. By comparison with band-structure and configuration-interaction cluster calculations our results support a model of CrO{sub 2} as a half-metallic ferromagnet with large exchange-splitting energy ({delta}{sub exch-split}{approx_equal}3.0 eV) and substantial correlation effects. (c) 2000 The American Physical Society.