Absolute differential and integral direct electron excitation cross sections have been measured for the three most intense autoionizing 3P → 3P¿ transitions in atomic oxygen (878, 792, and 770 ¿) and the first five members of the 3D¿ Rydberg series whose origin is the 1027 ¿ transition. Incident electron energies from 30 to 200 eV were used. Absolute values of the differential cross sections were calculated using the previously measured atomic oxygen 3P → 3S¿ (1304 ¿) cross sections were calculated using the previously measured atomic oxygen 3P → 3S¿ (1304 ¿) cross section of Vaughan and Doering (1987) as a secondary standard. The cross sections were much more strongly forward peaked at the higher laboratory incident energies than at low energies. The integral cross sections for the 878- and 792 ¿ transitions were identical within experimental error, both in shape and absolute magnitude. The peak values were 1.1--1.4¿10-17 cm2 at the maximum near 50 eV, about a factor of 3 lower than the total cross section deduced by Zipf and Kao (1986) from emission experiments. The 770 ¿ transition was approximately a factor of 4 weaker with the same shape. The 3P¿ Rydberg series cross sections decrease uniformly with increasing principal quantum number as expected. The peak of the 1027 ¿ origin transition is approximately 3.5¿10-18 cm2 at 50 eV, in satisfactory agreement with the emission cross section of Zipf and Erdman (1985). The present cross sections for the higher energy states suggest that the autoionizing transitions are a significant source of O+(4S) ions in the thermosphere, but not as strong a source as has been inferred on the basis of previous measurements. ¿ American Geophysical Union 1988