• by Wayne Friedman , March 13, 2009

George Clooney's somewhat secret return to "ER" helped NBC on Thursday night--but not enough.

Clooney boosted "ER" by 11% to a Nielsen preliminary 3.9 rating for the 18-49 demographic. This gave NBC an average 3.1 rating/8 share for the night, coming in at fourth place behind Fox. NBC was up from a 2.5/7 the week before.

NBC did tease viewers with on-air marketing pitches that some past doctors would be returning to the famous "ER." And while there were images of many previous physicians in the promo spots, Clooney was not among them. Analysts believe NBC was a little too secret in its efforts. Still, with other doctors continuing to make appearances through the final episode of the show, "ER" could gain more viewers in the coming weeks.

With "American Idol" out of the Thursday picture this week, some of the 8 p.m. shows saw gains. CBS' "Survivor" moved up one-tenth of a rating point to a 4.1/12 (winning the time period) and ABC's "Ugly Betty" grabbed two-tenths of a rating point to a 2.1/6. A new episode of CW's "Smallville" showed up with a 1.6/5 among both 18-49 viewers and 18-34 viewers, virtually on the same level as its previous original episodes.

The big ratings winner of the night was "Grey's Anatomy," which earned a 5.0/12 at 9 p.m. But that time period is now somewhat closer, especially since all ran original shows Thursday. "CSI" was second at a 4.2/10; NBC's "The Office" was right behind with a 4.0/10; Fox's "Hell's Kitchen" was fourth with a 3.5/9.

Among the 18-34 crowd at 9 p.m. "Grey's" won again with a 4.9/13, with NBC's "The Office" right behind at a 4.4/13.

While "ER" won the 10 p.m. time period, it didn't come without a fight. ABC's "Private Practice" grabbed a 3.5/9, four-tenths of a rating point behind the longtime NBC medical show. Also at 10 p.m., CBS' "Eleventh Hour" posted a 2.8/7.

For the night, all four big networks were closely bunched in the three-plus ratings range. CBS won with a 3.7/10; followed by ABC at 3.5/9; Fox at 3.2/8; NBC at 3.1/8; Univision at 1.8/5 and CW at 1.4/4.