The two chairs, one bearing the name of Michael Winner, the other of Sophia Loren, are at this moment at least appropriately occupied - separate, but decidedly unequal. Winner's got the classy one: a brown Naugahyde number with attachable arm rests.

"I don't know why," says Sophia Loren, pouting beautifully down at her canvas chair, "you have the comfortable one."

"I have it," her producer-director replies smartly, "because I'm a bit younger."

"Oh!" She is taken aback, but settles wisely on the refuge of laughter. "That's why I should have it." Sophia Loren is a year older than the man who is directing her in "Firepower," which was being shot yesterday at the Voice of America. It is an $8 million thriller about an illegal attempt by the U.S. government to get a multimillionaire financier, accused of fraud, back on U.S. soil. Sophia Loren is 43; she shrugs it off with a defiant toss of the red curls she and her hairdresser have worked so hard at keeping in place.

"Age is a condition - you have to cope with it as best you can. You have to know how to grow older or you become a caricature. I never think about the years that go by."

She smiles wryly. "Maybe it's because I look . . . okay."

She sits back, amused and pleased with her self-description, but highly and acutely aware of the effect she is creating at the Voice of America. Yes, Sophia Loren is setting in the offices of the Voice of America between takes, passing out a series of glamorous glossies (bare shoulders, head thrown back) autographed for the benefit of ecstatic secretaries.

With a logic peculiar to Hollywood, the office of VOA Director R. Peter Straus, where the shooting takes place is being gussied up to look like an office in the Justice Department - largely, it seems because VOA has a great view; and Sophia Loren, soberly attired in a black-and-white print dress and patent leather shoes that are the envy of her stand-in, is playing the part of a distraught widow, seemingly out for revenge.

There is, of course, nothing "okay" about her; it was the most inapposite word she could have chosen. All of Sophia Loren's features - the two-wide eyes, the aquiline nose, the too-full mouth - seems in perpetual battle with each other, as if vying for dominion of that large expanse of face. It is only in the aggregate that she is beautiful - and then formidably so.

And although she is certainly most attached to her own beauty (refusing to allow casual photographs of herself to be taken without her final approval), she is also occasionally willing to risk its absence. Last year she appeared in "A Special Day" as a frumphy, tired-looking matron.

"Yes, but that's the real me," she says earnestly. "That's really me on the inside. Although I think it's very embarassing to talk about one's face, I do have an interesting face. And the less makeup, the better it is. Then my soul comes out. Because makeup is like a barrier - you know?"

She arches the full length of her neck and leans back.

"It has always been like that," she continues airily. "I have never counted on my beauty. Never, I have never believed in it. There are so many beautiful people in this world, you can only reply on talent and on feelings. How can you reply on beauty? Beauty is something that comes and goes.

"You have to really get down and scratch yourself for talent. Of course," - a dark, strong hand waves away the obvious - "Of course I pretend to look sexy and glamorous. That's a game."

This is, in large measure, the basis of her phenomenal appeal - her wary and diffident analysis of who she is and what she has come to represent. Sophia Loren is one of those rare stars who mean quite as much to women as they do to men - the covers of all the ladies' magazines can attest to that. Certainly it's easy for the women to identify with her life: a single-minded pursuit to security and fidelity, personified by her husband, Carlo Ponti, who is more than 20 years her senior.

"It's an example I need a father badly," she says, nodding. "I had a father. I knew him. But he was never a father to us."

And as for fidelity - "If you do it, it means it's a part of your life. If I am faithful to my husband until now, it is for me the most natural thing," she explains gravely. "You can't plan a life of fidility. Otherwise you'd be a monster. And something I'm not is a monster.

"And I think men - they're always intelligent enough to know when they can and they can't. She allows a small movement of her wrist to suggest what men can and cannot do. "I never give them a chance to go too forward, so I never had a very hard time to make them go away."

Well, in part Carlo Ponti, himself, is as responsible for the appearance of discretion, as his wife is for its execution. During a break between takes, Sophia Loren asks her director if he can provide her with three tickets to a Broadway show Wednesday night, "so I can go with a girl and a friend of mine. My husband doesn't allow me to go out alone at night with just one person."

When asked about this, she looks for the first time - and last - mildly embarrassed.

"I don't like when people intrude in my life. Why help them writing things that are not true."

A barely perceptible shrug of disdain. Just a while back there were rumors of a possible rift in the Ponti-Loren marriage. "That's just this paparazzi school of journalism," she says with an abrupt jerk of her chin. "We are together as you see. Come back in 10 years and it will still be the same."

In a way, it's rather intriguing to contrast the temperament of Sophia Loren with that of her best-known co-star, the romantically adventurous Marcello Mastroianni - with whom she will soon star in a Lina Wertmuller picture (along with Giancarlo Giannini, which seems a bit redundant). Mastroianni is not exactly a Grow-Old-Along-With-Me kind of guy.

"Each time Marcello has a relationship with women," says the actress, "it's very, very serious. He goes all the way. He takes all the responsibility - which is very difficult for a man in his position.

Her luminous eyes - olive under the hot lights - widen in sympathy for her longtime friend. "When he thinks he's in love, he express himself a great deal. Not many men have the guts to do this. He's a very faithful man."

She pauses a fraction: "In his way."

And does she think - if there had been no Ponti - that she would have ended up with Mastroianni?

"Marcello?" She seems to be suppressing a laugh. "I never like to talk about absurd things."

She rises to redo a take for the umpteenth time, her head thrown back, her chin jutting forward, and her body (trim now, trimmer than we're ever seen it in the movies) swaying in time to some phantom music.

"De Sica," she will say proudly, "De Sica used to tell me, 'If you don't have music within you, you can be a traitor in life very easily.' He used to tell me I had music within me."

She always wanted to be an actress. It was a way out of a rough childhood in the slums of Naples; "It was a way out of anonymity," she says. In 1957 De Sica cast her in "Gold of Naples," her first real hit, and that was the end of anonymity for Sophia Loren.

"I know this is the dream of every girl who is a little . . . pretty," she says derisively. "But the interesting thing is I was never bitter, I never had a moment of despair. I thought always I would succeed. Well, never in this big a way - but I always thought that in one way or another I'd be a success, I'd be able to have a role."

And there, too, lies a great part of her appeal to the masses. There was, first of all, the struggle. "The struggle they've forgotten," she insists, but they can't be entirely true, since most of Sophia Loren's life was a struggle in one way or another: Much of it reads like a soap opera. When she married Ponti (who had been divorced), a recalcitrant Italian government charged him with bigamy. When that was settled, she tried to have children. When it seemed she couldn't have children, she delighted the world by becoming pregnant. Twice.

When that was accomplished, she had income tax problems. After that, a fire broke out in her Paris apartment building and she had to flee the premises during the night, clutching her two boys. More recently she has been plagued with charges of currency violations in Italy.

Somehow Sophia Loren, who has after all suffered no more and no less than many other women, seems to embody triumphant womanhood - at once fallible and formidable.

"I'm a very authentic person," she announces matter-of-factly. "I always say what I feel. I like if people tell me I'm wrong. If people tell me I'm wrong I never get offended.

"Maybe because I never consider myself a star. To be capricious, a little dictator - I hate that absolutely, I am one of the easiest people in the world to get along with."

She is utterly solemn as she says this, the full lips curling with emphasis. Sophia Loren with her two female companions, her hairdresser, her makeup man, for batch of glossies on hand, does not consider herself a star.

It's possible.

When Sophia Loren does not simile, small indentations under her eyes become visible through the dark makeup. It makes her look no better; it makes her look no worse. It makes her look as she is: 43. A resigned beauty.

"I think people love me very much," says Sophia Loren. "I am very grateful."