Uneasy rests the character actor’s soul.

Once protected by the studio system, character actors today face an ongoing squeeze for parts and money, as the gulf widens between the top stars and the rest. Even highly successful character actors fear, deep down, that turning down any part could be a mistake.

Actors, agents and managers variably trace the squeeze to the corporatization of Hollywood, the rise of the tentpole pic and the threatened SAG strike a few years ago.

Even TV, once considered the refuge of the character actor, has become more brutal in pay scales and hiring practices for those without a recurring gig, lending an added frisson to the pilot season. CBS, for example, rarely recasts character actors that have guested on any of its skeins that season, for fear viewers would be confused.

So deep is the ambivalence about their lot that many character actors balk at the label.

“To me, character actors are people who aren’t working,” one agency partner said while declining an interview on behalf of his client.

“It makes it seem like I weigh 200 pounds,” chafes the intensely svelte — and busy — Amy Aquino, who’s been laboring under the label since she started acting in film and TV around 20 years ago.

Yet just as many celebrate the term, shorthand for colorful thesps in pivotal roles as villains or quirky sidekicks. During the days of the studio system, repertory players such as Walter Brennan, Edward Everett Horton and Sydney Greenstreet could be relied upon to liven up the screen in secondary roles, in much the way Christopher Walken does today.

“It’s them that doesn’t end up kissing the girl,” says Susan Smith, a longtime agent who gave up her business four years ago to manage character actor clients Brian Dennehy, Kathy Bates and David Paymer.

Smith believes the struggle of character actors is really a veiled conversation about older actors, but others maintain that while ageism certainly exists — especially for women — the real problem is the fact that so much of the money is going to so few actors.

Tess Harper estimates “30 to 50 people in this town” are getting their quotes and “everyone else is making scale.”

“There was a time when I was making a good five-figure salary. Now it’s top of show,” she says, referring to pre-set scale for billing at the beginning of a TV show.

Last year, she couldn’t even make her SAG minimum to qualify for healthcare coverage.

“Twenty years ago you made scale on your first job, then never made scale again,” she says.

James Rebhorn says he hasn’t gotten his quote since 1999’s “Snow Falling on Cedars.” His income has dropped over the last five years, but he considers himself lucky because he’s been able to work steadily in theater, film and TV. He just finished a stint in Broadway hit “Twelve Angry Men.”

“I’m not worried about sending my kids to college,” Rebhorn says. “If I can keep the ball rolling, as I have thus far, no complaints.”

And longtime ICM agent Toni Howard, who reps Walken and Dennehy, maintains, “If you are a truly gifted character actor, your career will last a lifetime.”

Certainly, there’s a troupe of character actors steadily cast.

Rip Torn, now 74, has been working nonstop the past few years, and Celia Weston knocks on wood when she reports “it’s been pretty smooth sailing” since her first union job on a Broadway show in 1979.

“I’m lucky my quotes are honored,” Weston says.

Yet she admits to ambivalence over recently turning down a few roles.

Her rule of thumb: She’ll take scale if everyone’s getting scale. Similarly, Michael Murphy will take scale, but not on a studio movie.

Yet wide swaths of the rank-and-file only wish they could get more than “scale plus 10%” for their agent. Scale for principal roles starts at $700 for a day performer, up to $6,000 for a major role on an hour show, with weekly performers pulling down $2,411.

“The biggest beef among character actors is that it’s increasingly a minimum-only industry,” says Matt Kimbrough, who’s active in SAG politics. “It’s so entrenched now it’s taken for granted.”

Thesps say TV shows are using the day performer rate, a concession in the 2001 contract talks, to their advantage, turning skeds on their heads so an actor’s scenes can be shot in a day. Certain actors can demand the weekly performer rate; others aren’t so lucky.

And Kimbrough reports the union has received numerous reports about the Eye’s unwillingness to reuse guest thesps. The union has received similar reports about Lifetime.

“By and large they don’t want you,” affirms Harper. “You’re not on an approved list.”

On the plus side, regular series work — and there are plenty of recurring roles for character actors — can provide a healthy cushion for thesps. TV roles also generate much-needed residuals.

But the biggest upside to character work, regardless of the medium, is the longevity it affords certain actors.

“My friends who were beautiful blond ingenues in their 20s have a much tougher time, because where I’m competing with Academy Award winners, they’re competing against themselves 20 years ago,” Aquino says.

Bruce Davison likes to tell the story about when he was a “leading starlet in my early 20s” and Burt Lancaster pointed him toward character work. “He said, ‘You don’t want to be a leading man, kid. You got six movies and you’re washed up at 30.’ ”

Not that Davison immediately heeded that advice: “I had to get washed up after six pictures,” he admits.

Martin Landau, who first came to Hollywood when the studio system was in place and remains busy in his 70s, is old-school enough to believe “every actor plays a character — hopefully.” He points out that studios aren’t as interested in movies with characters as they are in tentpole pics and action movies with special effects.

And while some lament the future of character actors and the middle-class actor in general, others take a more optimistic view.

“These are very tough times — worse as it’s ever been — but I think something is going to come along to change this,” Murphy says. “I’ve been through this before,” he adds, citing the sea-change that occurred with “Easy Rider” back in the ’60s.

Besides, as any actor can tell you, it takes just one hit pilot or breakout role to reverse an actor’s fortunes.

Admits Kimbrough: “That’s what keeps us all going.”