NBC Nightly News topped the CBS Evening News in total viewers last week, and it's a three-way tie for the 25-54 demo. CBS's numbers are slipping. For the week of Sept. 18, NBC beat CBS by 492,000 and ABC by 602,000.

"Compared to Couric's first week, Evening News dropped by double digits, declining -24%, while ABC grew +10% and Nightly News increased the most at +15%. And versus Couric's second week, CBS continued to decline, off -2%, ABC was up only +1%, and Nightly News grew +5% among total viewers," NBC says.

For the week of Sept. 18:

Total viewers: NBC: 8,162,000 / CBS: 7,690,000 / ABC: 7,580,000

Homes: NBC: 5.7/12 / CBS: 5.5/11 / ABC: 5.4/11

25-54 demo: NBC: 2.1 / CBS: 2.1 / ABC: 2.1