- Marc Berman

NEW YORK Three weeks into the November 2008 sweeps, leadership is mixed between CBS and ABC, according to Nielsen Media Research. 

CBS remains the most-watched network, with 1.43 million more viewers than second-place ABC. And ABC and CBS are tied for No. 1 among adults 18-49, with losses for both networks in both categories from the comparable year-ago period. 

The five broadcast networks, in fact, are down from one year earlier, with an average loss of 3.63 million viewers (42.62 to 38.99 million) and 12 percent among adults 18-49 (14.5 to 12.7 rating). 

The biggest loser is Fox, with an erosion of 1.30 million viewers (8.05 to 6.75 million) and 19 percent in the demo (3.2/ 8 to 2.6/ 7).

Here are the final national results from Thursday, Oct. 30 through Wednesday, November 19 (with percent change versus the year-ago period in parentheses):

Total Viewers:

CBS: 11.74 million (- 3), ABC: 10.31 (- 8), NBC: 7.98 (- 5), Fox: 6.75 (-16), CW: 2.21 (-21)

Adults 18-49:

CBS: 3.1 rating/8 share (- 9), ABC: 3.1/ 8 (-14), NBC: 2.9/ 8 (- 9), Fox: 2.6/ 7 (-19), CW: 1.0/ 3 (- 9)

Adweek is a unit of the Nielsen Co.