By Peter Bowes In Los Angeles

Friends star Jennifer Aniston is on a mission to impress Hollywood's top brass.

After nine series of the Emmy-winning sitcom, in which she co-stars as Rachel Green, one of the six close friends living in New York, Aniston is preparing for the day the show finally comes to an end.

It is widely thought that the next season, due to start in the US in September, will be the last.

The actress acknowledges that it is time to start weaning the public away from Rachel.

"I have to do that in order to maybe be allowed back to do something else," she says. "It's my job as an actor to do other things - and see if anybody will buy it."

Friends made Aniston (left) a huge star

The looming crossroads in Aniston's career highlights the fickle nature of a business in which even the biggest stars feel insecure.

She says it has never been in her nature to assume that success was always round the corner.

"Until Friends, I really thought acting was... a job once a year, maybe," she explains.

"Even before I started working in Los Angeles, I don't know if it's right to say I wasn't very ambitious, but I had that thought a lot.

"The dream of maybe succeeding, or making money, at what I really want to do might not happen.

"And I just might be a professional waitress, and that was fine."

Acceptance

But Aniston was destined to become a major star - not least through her success as Rachel, but as one half of one of the most glamorous celebrity couples in the world.

Her marriage to Brad Pitt has been portrayed as both volatile and intensely loving.

Aniston says of her career: "When things did happen, which were really wonderful, I was really pleasantly surprised."

Aniston hopes there will be more roles after this latest film

But the actress is sounding as concerned about her future as LA wannabes searching for their first paying job.

She is worried that she may not be accepted in any other role than Rachel.

"I don't know whether anything's going to happen after this," she admits. "You never know."

But Aniston's concerns may be short-lived.

The actress is receiving positive reviews for her latest role in The Good Girl, which has just opened in the US.

She plays a shop assistant in a small Texas town who sees no future in her life.

Aniston says the film reflects many aspects of real life.

"It's everything - depending on where you are," she says. "Whether you're working at the retail rodeo or you're a successful actor, lawyer, doctor, writer whatever, you have moments.

"It's ebbs and flows, it's different because everybody's lives are different."

While the jury is out on Aniston's attempt to make the tricky transition from sitcom star to respected character actress on the big screen, there is unfinished business on the set of Friends.

Award

The burning question remains: Will Rachel end up with Ross or Joey? Aniston says she has no idea how the show will end.

"I leave that to the writers," she says. "I'm never good at speculating that stuff.

"I love being surprised every week - I really do. I love being excited to see what's round the corner. They never disappoint me."

The actress is equally coy about her chances of going home with an Emmy award next month.

Aniston is nominated in the category for outstanding lead actress in a comedy series for her role as Rachel.

She says even being in contention for such an honour makes her feel "nauseous".

"It's not my most comfortable arena," she adds.