NEW YORK (AP) — Preliminary Nielsen ratings suggest that Conan O'Brien won a hefty audience for his final hour hosting "The Tonight Show."

O'Brien scored a 7.0 rating for his farewell appearance on NBC Friday, compared to a 2.5 rating for CBS' "Late Show with David Letterman" and, on ABC, a 2.8 for "Nightline" followed by 1.3 for "Jimmy Kimmel Live!"

These early figures, which reflect viewership in roughly 70 percent of the country, can't be reliably translated into audience numbers. An accurate viewer count is expected later this week.

O'Brien exited NBC after tumultuous negotiations that resulted in a severance deal signed last Thursday. His departure ends nearly eight low-rated months at "The Tonight Show," and, before that, 16 years hosting "Late Night."

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