Helen Hayes plays TV's new Miss Marple of the Agatha Christie novels, but she prefers the original Miss Marple, the late Margaret Rutherford. (Miss Hayes stars in A Caribbean Mystery - CBS, Saturday, 9-11 p.m.)
''I adored her,'' explains Miss Hayes at a studio on West 57th Street where I interrupt her as she is recording her daily syndicated radio commentary, ''The Best Years'' (check local radio listings). She is a trim and tiny woman, her straightforwardly gray hair pulled back simply.
''At first I refused to accept the role because I adored her so, and I didn't want to follow Margaret Rutherford as Miss Marple because I can't be that funny and, anyway, I'm not that kind of funny.'' She took the role, she added, because of her friendship with Warner Bros. TV head Alan Shayne.
''Did you know that Agatha Christie's sister and the solicitor in charge of her estate did not like Margaret Rutherford in the role? When they saw me in a mercifully small part recently (I was killed off quickly) in a TV version of ''Murder Is Easy'' they said, 'That's our Miss Marple.'
''Well, I don't care. Margaret Rutherford is my Miss Marple and the world's Miss Marple.''
The interviewer explains that he has previewed the show and found Miss Hayes a very different, but still delightful, Miss Marple. Although it is a trivial entertainment - the show does not pretend to be anything else - it is filled with Christie's marvelously misleading clues and is chock-full of valid suspects. It appeared to this viewer that Miss Hayes enjoyed playing the role.
She laughs, as she does often during the interview. ''Well, that shows I haven't lost my art. Boy, was I glad when it was finished. We worked 10 hours a day, six days a week in Santa Barbara, Calif.
''It was freezing cold, and since it was supposed to be taking place in the Caribbean, I had to wear light clothes. But under those light clothes I was wearing thermal underwear and shivering. At the end of the day I was too tired to eat - I'd just fall into bed and cuddle up under many covers. It was hardship. That's the way television is.''
Does she expect to do any more television?
''I doubt it.''
That's not a definite no. What if another friend approaches her with still another project?
''Oh, dear, I'm just going to have to keep away from friends,'' she giggles. But it is as difficult to imagine Miss Hayes keeping away from friends as it is to imagine her totally retired from acting. And there's still cinema.
''I never enjoyed myself in the movies. I enjoyed the theater because I could have my own dreams about what I was like on the stage and nobody could contradict what I had in my head. But when I see myself in the movies, there it is and I can't argue with it. So I don't enjoy that.''
Although the theatergoing public tends to remember her best for her role as Queen Victoria in ''Victoria Regina,'' Miss Hayes now recalls that the play ''went on a little too long for me - I don't like to get mired in a role for four years.
''The one that was just right in time and in the role itself was 'What Every Woman Knows,' that lovely Barrie play. I played it for almost a year and enjoyed every moment of it.''
''The Best Years'' is Miss Hayes's syndicated radio show. (If it is not listed in your area, you can call your favorite local station and let it know it's syndicated by Independent Radio Network, Greenwich, Conn.) The program seems to mean a great deal to her now that she is limiting her work.
''It's a whole new career, a very stimulating one,'' she explains. Like a very young girl, her enthusiasm animates her face, ''I have been a communicator from the age of 6 when I first acted, and I have to keep on communicating,'' she says. ''I have something very important to communicate. Hope and inspiration and sound advice. Tips to people over 65 . . . and sometimes even younger.
''You know, I say the word 'old' because all the other words like 'elderly' and 'senior citizen' are evasive. I am proud of my 82 years and I'm not at all sensitive about talking to other old people.
''Our society mostly ignores old people because it is sometimes fearful and painful to confront the business of age. We have a youth culture and everything is aimed at youth. I was very impressed when I was in Korea just after the war there with the attitude of Orientals toward the old. They were looked up to and revered.''
Does Miss Hayes see a change in our society in its attitude toward age?
''I hope so. But it's hard to change now because the family as an institution is so shaky, people are so scattered, nobody has big houses, etc. When I was growing up, my Granny Hayes (her mother's mother) lived with us and she was such an enriching force in my growing years. She was that lap I could always crawl into if things got too tough. She was that story teller who sparked my imagination, infinitely better than a TV set.
''Nowadays it would be very hard to bridge that age gap. If I ever tried to live with my grandchildren, 17 and 23, we'd go crazy. There are no bridges. We get along fine, but we wouldn't if we were living together.''
What does radio commentator Hayes hope to bring to her audience in the three-minute commentaries which are now carried by 175 stations across the country?
''I want to soothe hurts, awaken new will to contribute by convincing my listeners that we old folk have a lot to contribute. . . .''
Doesn't Miss Hayes feel a bit out of the mainstream now that she has forsaken the theater?
She ponders for a moment and I am fearful that I have saddened her. But her eyes start sparkling and the smile broadens. ''Sometimes I see a play and I feel a bit wistful and think I'd love to be up there. I guess I will always have a little wistfulness about the stage.
''But I have a house in Nyack (New York) and a house in Cuernavaca (Mexico) and I travel a lot.''
Although Miss Hayes is quite willing to talk about her past, there seems to be very little nostalgia in her makeup. She simply integrates the past into her present. I tell her that and she laughs. ''That's an interesting - and accurate - observation,'' she comments. ''Heavens, there's no melancholy.
''After Charlie (her husband, writer Charles MacArthur) died, everybody tried to get me to move out of our house in Nyack. There are so many memories connected with it, they would warn.
''Well, I'm so grateful I never moved. I love the memories. I can't move in that house without something wonderful happening in my heart. I see pictures of so many happy days. Charlie and my Mary (her daughter who died at an early age). They're there and nothing can take them away. Maybe that's immortality.''
She is quiet for a moment. But then she brightens up again.
''You must remember,'' she says, ''all through my life in the theater, I was kept from knowing the wonders of this world that we have been graced and blessed to inhabit. So there isn't a day now that I don't find something exciting, because I am just like a bird taken out of a cage and set free.''