Acting her age comes naturally for Sharon Stone in the new movie Catwoman. She tells Steve Pratt how she has overcome personal trauma to claw her way back to the top.

Sharon Stone crossed her legs in Basic Instinct and, in a flash, achieved movie immortality. The former Miss Pennsylvania, model and Playboy pin-up was elevated from B-movie actress to screen icon as an icepick-wielding bisexual killer in the steamy thriller.

Building a career based on that brief, revealing moment proved elusive with appearances in a succession of mostly bad movies - Intersection, Sliver, Simpatico, Last Dance, Sphere and Gloria - that were quickly forgotten.

Only Martin Scorsese's Casino brought her any prestige, earning her an Oscar nomination. It took a brain haemorrhage three years ago to put her back in the headlines.

This life-threatening illness, coupled with three marriages, many more bad movies, an adoption, and a reputation as a diva, gave her an incident-packed existence wholly suitable for a glamorous Hollywood movie star. "One more thing and I'd be a country and western song," she jokes.

Getting over illness and adopting a child have given her a fresh outlook on her career, which has become less important to her now. "I'm back working but I've been through so many things. I like work but it's not my life any more, it's part of my life."

She's always liked watching old movies in which the likes of Joan Crawford played bad girls, so she's pleased to be wicked in her comeback movie Catwoman. She leaves Halle Berry to squeeze into a leather catsuit in the title role, content to have a ball as the villain, the supermodel wife of the boss of a "youth and beauty at all costs" cosmetics corporation.

The film hasn't done as well as hoped at the US box office but the promotional bandwagon has served to remind people that Stone is back in town and willing to talk about one of the picture's themes, the obsession with beauty and ageing. She's coping well with both. At 46, with a shorter hairstyle and trim shape, she's looking good and without help from the surgeon's knife.

'When we were doing the movie and I saw Halle in the catsuit, I went straight to the gym and worked out all the time we were shooting. Once she took the catsuit off, I never worked out again," she says.

"I'm not big on plastic surgery for me. But I don't fault it for someone who wants it. You have to do what makes you feel good, but it's not my thing."

Her Catwoman character complains about women being discarded when they reach 40. The speech was put into the script following a conversation she had with producer Denise Di Novi. "We were talking about what happened when I cavalierly started announcing that I was 40," recalls Stone.

"I was 39 and working like mad, then told everyone I'd hit 40. I think they misheard that I said leprosy. Suddenly I didn't work. Denise put it in this movie in a very interesting way.

"I think there was a truth at one time that you couldn't get good work after a certain age. Now, things have evolved because a lot of us have held the course of being proud of being 40 and being interesting and having life to bring to film and to our parts, and not being particularly interested in pretending to be 35 for seven years.

"There has been an evolution where you can be 45 and work in film and say you are 45, and have an interesting career."

Apart from Casino, her work has tended to take second place to Sharon the sex symbol. Perhaps age will allow her to flex her acting muscles more. She's certainly aware that being in the public eye casts her as a role model living life under the scrutiny of the media.

To be a role model, she suggests, you have to be willing to fail in public. The important thing is not how you fall but how you get up. She and Catwoman co-star Halle Berry have both experienced this with personal and marriage problems. "Neither of us have tried to pretend to be perfect. We've had crises in our lives and successes in our lives," she says.

They're both mothers in what she calls non-traditional ways. Stone has a son, Roan, now four, adopted when married to newspaper editor Phil Bernstein. Berry has adopted the teenage daughter of her ex-husband Eric Benet.

"We both try to succeed in our craft as actresses in non-traditional ways. We don't believe that you can only play certain roles to show your talent. We feel that you can be attractive and not just use your beauty as a shallow thing, but explore the fact that sometimes being beautiful means you feel so not beautiful because you've been seen as a shell.

"There are so many ways that we've wanted to show women that you can be more. When you want to be that, very often the press wants to show just how much less you are. There's a constant need to stand in the glare of that while people are trying to undress you and show that you are less. So it's a way to try to be a role model to say, 'You may be able to say what you want about who I am, but I will be able to stand the distance of the glare of that'. For me, sometimes just standing there while that passes is enough."

Saying nice things about Berry in public compensates for the hard time Stone's character gives her in Catwoman as the pair sharpen their claws for a cat fight at the movie's climax. She loved the way director Pitof chose to create the fight sequence. Instead of making it a wild, on-wire effects sequence, he made it like a bar brawl.

"I thought that made it much more interesting than some hair-pulling contest or exaggerated thing," she says. "We had fantastic stunt doubles who taught us a lot so we could do a lot for ourselves and then, in our close-ups, were able to do some really interesting stuff."

Playing the baddy was "so fun", she adds. "The villain is always the best part. No one is going to come up and say, 'Your character wouldn't do that' because your character would do anything."

Her son was on the set but she feels he's too young to see the movie. "Also, I don't think he needs to see me killing people," she says. "It was so cute when Halle came on the set as Catwoman he was completely speechless and overwhelmed. Then she went in front of the camera and he went, 'She's not the real Catwoman, she's just pretend'."

Stone didn't collect comic books as a child, but her son is crazy for them. "We're already at the news stand buying comic books. It's so adorable."

She's clearly not going to waste the comeback opportunities that the release of Catwoman will bring. Surprisingly, one project under consideration is the long-delayed Basic Instinct sequel. Considering the legacy of the original, which saw her typecast as a femme fatale, you'd have thought that she'd have wanted to move on.

She also has plans to direct a movie, although unwilling to be more forthcoming about the details. "I can't say what it is yet because we have just gone into production and we are just writing the script," she says.

* Catwoman (12A) opens in cinemas on Thursday.