NBC’s “Today” show has widened its lead over ABC’s “Good Morning America” since Katie Couric left as Matt Lauer’s co-anchor May 31. Data from Nielsen Media Research shows that “Today’s” margin of victory June 1 through June 14 grew to an average of 1.13 million viewers.

That lead is “Today’s” largest — except for the week Ms. Couric signed off and when “Today” was in Italy for the Torino Olympics — since Aug. 30, 2004. Until Ms. Couric’s final day, “Today” had a season-to-date average lead over “GMA” of 854,000 viewers.

For the week of June 5, “Today’s” total viewership was up 2 percent from the comparable week in 2005. The program averaged 5.6 million viewers, followed by “GMA” (4.5 million viewers) and CBS’s “The Early Show” (2.4 million).