UPDATE 1-'ER' finale draws 16.4 million TV viewers

* Show boosted careers of actors such as George Clooney

* Viewership slipped as original cast members bowed out (Updates with higher figure of 16.4 million from NBC)

By Alex Dobuzinskis

LOS ANGELES, April 3 (Reuters) - NBC hospital drama "ER" ended its 15-year run by drawing 16.4 million viewers for its final episode, the highest viewership for a drama finale since 1996, the U.S. network said on Friday.

The two-hour show on Thursday night brought back "ER" alumni Noah Wyle and Eriq La Salle, as the staff at County General Hospital in Chicago treated a dying woman in labor, an AIDS patient and a comatose teenager with alcohol poisoning.

The last scene showed emergency room staff wheeling in burn victims from a plant explosion as Chicago's famous elevated train passed overhead, giving audiences the sense that while a TV show may end, life goes on.

The 16.4 million figure was the highest for a U.S. drama finale since the CBS show "Murder, She Wrote" in 1996, which drew 16.5 million viewers, NBC (GE.N) said.

Earlier on Friday the network said the show had drawn 16.2 million viewers.

Throughout its run on U.S. television, "ER" boosted the careers of actors like Wyle, La Salle and George Clooney, who played Dr. Doug Ross on the show until 1999.