A Leading Light : Movies: James Prideaux’s third TV film for Katharine Hepburn, airing Sunday night on CBS, may signal the end of the leading lady era.

For James Prideaux, Sunday night signals a symbolic write of passage.

The time when great actresses walked the Earth seems to be ending as Katharine Hepburn plays what some have said is her final role in the CBS Sunday night movie “The Man Upstairs,” written and co-produced by Prideaux.

Here we have another of those generational things, one in which the Hepburn leading ladies of this world dissolve and in their place . . . the emergence of the Madonna Era.

Perhaps.

But before that might happen, Prideaux suggests our considering another possibility, the Linda Purl era.

Linda Purl?

Prideaux sits opposite a richly decorated mirror of French ancestry in his West Hollywood apartment and office. The mirror, he says, was left to him by the late Judith Anderson. She was one of several actresses he knew, women who dominated theaters and sound stages and for whom he wrote.

His list of power actresses: Judith Anderson: “bigger than life”; Geraldine Page: “the one true genius, absolute magic”; Elizabeth Taylor; Julie Harris; Meryl Streep; Hepburn.

But, please, he insists forcefully, “don’t classify me as a woman’s writer. Don’t forget ‘Lyndon.’ It’s still out there, my one-man play about the former President.”

With or without “Lyndon,” Prideaux’s list is almost a roll call of the great actresses of the last half of this century.

But the roll call and his list have grown short, victims of guaranteed human mortality, cruel show-business economics and the often bitter and changing tastes of audiences.

In recent years, the American theater has become product-driven rather than star-driven. (Say theater and what actress’s name jumps to mind?) Scripts and spectacle are the stars.

Studio factories ages ago ceased producing long-running, carefully nurtured film stars, especially actresses, preferring to bring out new, look-alike models each year.

Alone on Prideaux’s list, Julie Harris remains active in the theater, Streep in films. Dame Judith died last January. Geraldine Page five years ago. Elizabeth’s Taylor’s last acting role was in the still-to-be-released 1987 movie “Young Toscanini,” while more recently her acting voice will be heard in a “Simpsons” episode, which airs tonight.

Strong women with strong stage and screen presence no longer dominate acting. Jessica Tandy may command certain roles in films and on the stage. In television, Angela Lansbury and Roseanne Arnold can control their own series’ destinies while other actresses search for movie-of-the week stardom. In films, even an established star like Streep finds there are no sure scripts, as witness this year’s “Death Becomes Her.”

“The entertainment businesses have changed enormously,” says Richard Jewell, a USC professor of film history. “The opportunities to become a Katharine Hepburn, to play a classic kind of performance, are so few now. There aren’t as many films being made as during Hepburn’s time when such other actresses as Bette Davis, Barbara Stanwyck and Marlene Dietrich also commanded star vehicles. Today if you get a break the best you can hope for is to keep working.”

Work does make a difference. It keeps you up front, solvent and, in the eyes of some, a star. Work if you can get it.

Prideaux and Hepburn have become almost a self-generating, complementary work force. Sunday’s “The Man Upstairs” is the third television play in the last six years that Prideaux wrote and co-produced for Hepburn, along with director George Schaefer. In 1986 it was “Mrs. Delafield Wants to Marry” and in 1988 “Laura Lansing Slept Here.”

Of the actresses Prideaux has written for, Julie Harris at 66 still hits the road, called by one commentator, “the first lady of touring.” She commissions works, takes on new roles, goes on frequent tours, such as this year’s traveling version of “Lettice and Lovage.”

But who among the younger actresses is there to fill the obviously growing void?

Prideaux’s unblinking answer: Linda Purl, whom he calls, still not blinking, “the greatest young stage actress of our time.” Strong praise, especially when he doesn’t even have a script ready to show her.

Purl matches Harris in work habits. Still in her 30s, Purl has appeared in more than 25 TV movies (last summer’s “Body Language” on USA Network) and several feature films (“Crazy Mama”). Purl earlier appeared with Julie Harris in Prideaux’s “Tusitala,” a play about Robert Louis Stevenson’s last years in Samoa. “I have followed her since,” he says. “She works a lot. In my mind she clearly is the best of the young actresses.”

If the single star system for actresses is endangered, Prideaux offers another suggestion, one he calls “pairings.”

It’s celebrity mix and match. Instead of one big star and one script, he would would take two medium-size stars, one script and develop “an event,” something Hollywood talent agencies call packaging, putting together star names with star writers and star directors.

Once a Hollywood pairing meant Tracy and Hepburn, Bogart and Bacall. But in our present world of managed expectations where less is more, Prideaux would bring together, say, Ann-Margret and Albert Finney in a television movie. He says the names, and his look conveys imagine the possibilities . Then there is more, Sophia Loren and Luke Perry.

Or, as it almost came to pass, Katharine Hepburn and Burt Reynolds.

That pairing almost did become an event, thanks to the collaborative, leveraged way of doing business in Hollywood.

Prideaux was going through the early writer’s exercise of plot-making--looking for a salable, network story, thinking of perhaps one more television play for his old friend, Hepburn. He was also thinking Christmas story, a show-business evergreen with residuals forever.

Reynolds, who stars in the CBS series “Evening Shade,” has his own production company and was looking for a TV movie project.

Prideaux talked of his Christmas idea and the pairing of Hepburn and, of course, Reynolds.

Reynolds liked the idea. CBS, too.

But by the time the script was finished and had everyone’s blessings, Reynolds was off to Florida on a movie project and Christmas was still coming. But the production would still be done by his company.

Jon Voight was nominated, except he had a date to make a film.

CBS came up with Ryan O’Neal, who had co-starred in a brief and unsuccessful 1991 series with Farrah Fawcett, “Good Sports.” That aborted series also came from CBS.

It wasn’t quite the pairing Prideaux had in mind. “I was taken aback,” he says, “but when I introduced the two and Kate sized him up I knew that there was chemistry at work.”

How much chemistry there is will be left to the critics and to a public that still seems to buy in to the Hepburn image. Another look at her career will be offered in a January cable special.

Prideaux goes back almost 25 years with Hepburn, having offered her the lead in his play “The Last of Mrs. Lincoln,” which she turned down believing her acting career was over and she was looking to direct.

“Too bad she didn’t direct,” Prideaux says. “She would have been a crackerjack director. She kept the screen alive.”

With his Hepburn connection, Prideaux turned to Hollywood’s new way of doing business. He became writer and producer. “Here I had a script and the biggest star in the world. Why should I give up control to others? As a producer I can protect my script. I have some influence in casting, go on the set every day, see the dailies, see how the editing is going. It gives me clout and some artistic control.”

For this writer and this actress, two different rites of passage.