From 1977 to 1982, Nancy Marchand was publisher Margaret Pynchon to Ed Asner's title character on TV's "Lou Grant."

Within the past few weeks, each had an opportunity to comment on the experience.Miss Marchand, appearing now in the off-Broadway smash, "The Cocktail Hour," called Asner "a very generous guy. He was our leader. He made it a very pleasant experience. The whole `Lou Grant' thing was a wonderful experience."

The more outspoken Asner, now appearing in a touring pre-Broadway run of "Born Yesterday," asked, in turn, of Miss Marchand:

"How is that battle-ax? She is unbelievable. There are very few people I would inwardly grovel at in terms of their work. I would tend to do that with Nancy. I have bones to pick with her personally, but in terms of being an actress . . . .

"There was a show wherein (her character) brought in a new idea man, and his ideas were driving me nuts and disrupting the newspaper like mad, and I wanted to kick (him) out, and finally it came down to a confrontation between me and him in her office. Now we know that I'm the star of the show and that it's going to be funny and strange and trend-setting if she fires me, and she gives this speech where she makes this decision.

"You can smell in the script from the second line that the other guy is going to get the heave-ho. But the way she played it better and better each time, our doubt was left up in the air longer and longer into the speech. By the time she got to her closeup, you really couldn't tell which way she was going. Nothing false. All true. She suspended our knowledge until the end of the speech. That to me - it may not impress you - it bowled me over. And she was capable of doing this all the time."

It's that internal life of hers, that way of inhabiting a role so that everything seems to be happening spontaneously, that allows her to fill a performance with particulars. You watch her because you know something is going on in her. She's listening and concentrating, not just marking time until her next line.

In "The Cocktail Hour," at New York's Promenade Theatre, she acts a woman whose adult son has come home for his parents' approval for a play he has written. The play, to their chagrin, is about them. The mother would prefer he adapt the play into a novel. That way, she feels, almost no one will notice it.

Just a few blocks from the theater in her high-ceilinged Upper West Side apartment, Miss Marchand talks about her life and her work.

"We moved here, oh, 25 years ago," she says. "Lots of closets here. And did you see the courtyard (around which her apartment building and several others are clustered)? The children played hopscotch and mucked about there."

The children are grown and gone. Her husband of 36 years is actor Paul Sparer.

Despite 40 years of theater experience, it was her weekly appearances on "Lou Grant" that caused her celebrity to explode. It had, she said, a downside.

"You should see the the piles and piles and piles of letters I have to answer and the requests for 8-by-10s, and `by the way, Grandpa's birthday is next week, and it would be great if you sent an autographed picture.' And that gets into answering and photos and postage and envelopes and it goes on and on and on.

"I find all those letters an imposition. I suppose that's snooty. But I try whenever I'm performing to give it my absolute best. I really try. I never phone it in. And I just kind of think: Gimme a break. What else do you want? It's very nice that people like my work, but I really don't like that kind of thing.

"I lo-o-o-o-ve to act, and I've been very lucky. I have always been very busy doing something. I'm the luckiest person in the world. I've got three great kids. I've got two wonderful grandchildren. I've got a wonderful husband. I have a large body of work that I can look back on, and of some of it I can say: `That wasn't so bad."'