Clooney cameo boosts ER ratings

Clooney received his fourth Oscar nomination for Michael Clayton in 2008

George Clooney's brief return to US TV in medical series ER gave the show its highest ratings in two years, as the long-running series draws to a close.

Clooney's comeback episode, which also featured former regulars Noah Wyle (Dr Carter) and Eriq La Salle (Dr Benton) saw a 23% increase in viewers.

ER, US TV's top-rated drama for several years in the 1990s, thrust Clooney, 47, into the Hollywood spotlight.

The actor left in 1999 to pursue a film career, winning an Oscar in 2005.

In the same year that he picked up the award for best supporting actor in Syriana, Clooney was also nominated for best director and best original screenplay for his work on Good Night, and Good Luck.

Ratings slump

ER, set in the emergency room of a fictional Chicago hospital, was the most popular show on television in 1995, averaging 32 million viewers a week.

The series was created by the late Jurassic Park author Michael Crichton

But - now in its 15th, and final, series - the show barely manages 8 million viewers per episode.

After Clooney made a brief cameo on the show in 2000 - which saw him settling down with his on-screen partner Carol Hathaway (played by Julianna Margulies) - it was widely reported he would not return.

Other former stars of the show have also featured in the final series, including Laura Innes (Dr Weaver) and Anthony Edwards (Dr Greene) - whose character appeared in flashback, having died of brain cancer in 2002.

Thursday's Old Times episode, which also marked a guest appearance by Susan Sarandon, gave ER it best ratings since February 2007 with an audience average of 10.7 million.

The Clooney episode will screen on More4 on 14 May. The final episode will air in the US on 2 April.