• by Wayne Friedman , November 4, 2011

Broadcast late-night programming has seemingly never been closer among key viewers.

For the most current reporting week of October 24, all three major networks' programs that begin networks' start of late-night time periods -- 11:30 EST/PST -- ABC's "Nightline," CBS's "Late Show with David Letterman" and NBC's "The Tonight Show with Jay Leno" -- are in a Nielsen-ratings statistical dead-heat when it comes to two key viewing groups, adults 18-49 and adults 25-54.

All three are posting a 1.2 rating in adults 25-54 and a 0.9 rating in adults 18-49.

A rating is a percentage point of all U.S. TV homes or U.S. TV viewers.

Looking at estimated specific viewer numbers, "Nightline" continues to have a slight edge in these two categories, averaging 1.165 million 18-49 viewers and 1.446 million 25-54 viewers. For the fourth week in a row, it has had the best late-night numbers among 18-49 and 25-54 viewers.

Just looking at the entertainment shows, CBS's "Late Show" continues to find some momentum against its archrival NBC's "Tonight Show." In the most current week it pulled in 1.108 million 18-49 viewers -- slightly more than "Tonight Show," which scored 1.091 million. It also barely topped "Tonight Show" with older 25-54 viewers, 1.437 million to 1.418 million.

NBC can tout one prize -- total viewers -- for this week. Here,"Tonight Show" is pulling 3.819 million viewers to "Nightline"'s 3.787 million, with "Late Show" well back in third place at 3.215 million.

Overall, however, on a season-to-date basis, ABC's "Nightline" still claims leadership among total viewers.