Marina Sirtis doesn't want her fans to be disappointed, but she didn't become an actress just to be on "Star Trek: The Next Generation."

"I became an actress to work on anything," said Sirtis, who plays the sexy Counselor Deanna Troi on the syndicated show."If you are your character all the time . . . you get so associated with that character all the time that you possibly may not work very much afterward. I really want to make a differentiation between Troi and Marina because I want to work."

This is Sirtis' fourth season on the show as Troi, the half-human, half-Betazoid ship's counselor whose empathic powers enable her to sense the emotions of others. She is appearing at Star Trek conventions across the country. But, she said, she's leaving the Deanna Troi character in California.

"When I do conventions, everyone is really surprised at the difference," said the London native in a telephone interview from her Hollywood home. "And I always tell them to go get their money back. I don't do Troi when I'm me. I really try and disillusion them about me. I think it's dangerous not to dispel the image."

She does that with what she calls "an hour of stand-up" at conventions. "I think people are pretty surprised at some of the things I come out with. I think some people are disappointed. . . . That's a shame."

Off the set, she said, there are many differences between her and the composed and mysterious character she plays.

"I think I'm pretty transparent. I don't even think you have to get inside my head because I'm so vocal," she said. "Everyone knows where they stand with me. . . . I'm the classic person who blows up and 10 minutes later I'm giving you a hug. The person I've blown up at may not necessarily be over it by then if I've been a bit nasty. But as far as I'm concerned, it's dealt with."

Off screen, she sounds different, too. Her British accent, although fading, stands out with words that come quickly, words like "quite" and "smashing."

"I'm quite zany, I suppose, for want of a better word, and she (Deanna Troi) isn't. . . . And when you take that away from Marina it's quite easy to do (Troi's) accent."

Born to Greek parents, the 30-year-old actress grew up in London, where she attended the Guildhall School of Music and Drama. Before moving to Los Angeles in 1986, she already had gotten accustomed to a cult following when she played Magenta in a British touring production of "The Rocky Horror Show."

"We had fans following us around everywhere. I mean, we said `Rocky Horror Show' and doors would open. I call it my `Star Trek' training. I think next to `Star Trek,' it was my most enjoyable job."

Sirtis feels certain that "Next Generation" movies will be made when the series ends.

"Well, I think it's pretty much of a given. Without giving too much away, I think in the movie they pretty much hand it over to us at the end of `Star Trek VI.' "

If that happens, fans will be pleased to know that she expects to be a member of the movie cast. "I always say to the fans, `If I'm not in it, I've been fired.' "

Although she has no input on scripts and episodes, Sirtis admitted to occasionally complaining that Troi doesn't get action spots. That recently changed, but it wasn't exactly what she had expected. In shooting the "Night Terrors" episode that aired Saturday night, Sirtis said she "got to fly like Peter Pan."

"It was great when it happened but the thought of it was absolutely terrifying because I'm afraid of heights. . . . Then they said I get to fly in the episode and I said, `Oh, great. Thanks a lot. The one thing that I'm really scared to do.' But it was fun."

Sirtis said she has a couple of favorite "Next Generation" episodes. Loyal watchers will remember "The Offspring" in which Lt. Cmdr. Data, the ship's android, created an android like himself and called it his daughter. In another show, Sirtis said she got to do something totally different with her character when Troi lost her empathic powers: She got nasty.

"I had some really great lines in that one, like, I said to the captain, `Spare me the inspirational anecdotes.' I was psycho from hell in that one."