The British star of the hit US series ER claims she has become a victim of Hollywood's culture of ageism after the show's producers refused to renew her contract.

Alex Kingston, who has played surgeon Elizabeth Corday in the award-winning show for seven years, was told that her character is being written out at the end of the current series.

The 41-year-old says the decision is further proof that Hollywood is obsessed with youth.

"I suddenly felt very old surrounded by these young 20-somethings," she complained in a Radio Times interview. "Does it mean that I'm the geriatric that's being pushed out because she's too old?

"[The show] definitely seems to be taking a different tone. I understand it needs to keep reinventing itself in order to keep going and apparently I, according to the producers and the writers, am part of the old fogeys who are no longer interesting. In that respect it's a shame. It's fine to have young med students, but you need to have figures of authority, people of different ages, races, shapes and sizes."

Ms Kingston's comments are the latest in a series of outbursts from high-profile actors, including Kim Cattrall from Sex and the City and Helen Mirren, who say the roles available to them dry up once they reach their late 30s or early 40s.

They complain that they are not in demand again until they are much older when more "character roles" start appearing.

Ms Kingston, who was once married to Ralph Fiennes, admits that her annual pay packet of more than £2.3m may also have affected the producers' decision.

"I know for a fact that the newcomers are not getting much at all," she said. Ms Kingston lives in California with her second husband, Florian Haertel, and their three-year-old daughter Salome. She still has more episodes of ER to film and says she has no idea how she will be written out.

"I had an idea of what was going to happen and it was something I firmly rejected," she said. "They were planning to get me involved with yet another man, and I'm already juggling two." The actor is returning to the UK to make an independent British film and to develop a TV show.

"Scariness comes from not knowing whether I can do it any more, because I've been playing one role for so long," she said. "Admittedly, I've done little bits and pieces, but I'm very excited about getting back to the UK."