NEW YORK – Replete with musicals, revivals and foreign imports, the 1999-2000 Broadway season has nearly abandoned the new American play. Which isn’t to say the species is heading for extinction in the New York legit world. In fact, as artistic directors at several of the city’s not-for-profit theater companies tell it, 10 or 20 years from now, people may look back on turn-of-the-millennium Gotham as a golden age for American scribes.

Given that not-for-profits are the almost exclusive domain of contemporary drama, signs that the tide is changing come from the most influential quarters. As artistic director of Lincoln Center Theater, Andre Bishop and LCT exec producer Bernard Gersten head the largest of nonprofit venues.

“Twenty years ago, all these not-for-profit theaters were fairly unknown, they weren’t reviewed very often, they weren’t widely attended,” recalls Bishop, who prior to his decadelong tenure at LCT was literary manager and then assistant director of the much smaller but prestigious Playwrights Horizon.

“All these young writers went to these theaters and functioned quite happily, quite innocently and almost anonymously,” Bishop adds. “Now what’s happened with the mixture of the commercial and the not-for-profit worlds and the need for the two to coexist and feed off each other — sometimes in a good way, sometimes not — is that whatever opens at any little place is suddenly in the public eye. The not-for-profit theaters have suddenly become the establishment, where 20 years ago they were not.”

Two decades ago, the establishment, i.e. Broadway, produced new American plays. Until recently, however, the form has been given precious little exposure on the Great White Way. But with little for critics to celebrate in the way of original drama, the media focus has shifted.

“Most of the real theater that’s being done in this town is not-for-profit,” says Robert LuPone, co-artistic director of MCC Theater, now in its 14th year.

Bernard Telsey, LuPone’s partner, points to their mission: “Today, no one is producing a new play by an American on Broadway. Years ago, it happened all the time.”

He gives “Children of a Lesser God” as an example. “It would never be done on Broadway today. It would be done not-for-profit and then moved uptown.”

Or maybe across town. MCC’s 1998 production of Margaret Edson’s Pulitzer Prize winner “Wit” is in its second year at a commercial Off Broadway house in the Union Square East theater district.

“A Broadway theater owner wouldn’t give us a theater,” Telsey recalls, and so MCC produced the show itself — with help from some commercially minded friends.

How the not-for-profits and their “friends” function is very much at the crux of what Bishop points to when he speaks of the “need for the two to coexist and feed off each other.”

In the case of “Wit,” MCC and Connecticut’s Long Wharf Theatre, where the play originally was staged, are lead producers of its current Off Broadway incarnation. The two companies raised most of the money, but partnered with commercial producer Daryl Roth, who also claims a piece of the play but didn’t come into the project until its commercial transfer.

Regarding MCC’s upcoming season, a conglomerate of legit producers has been involved from the get-go with the company’s initial offering, the new play “Trudy Blue” by Marsha Norman (“‘Night, Mother”).

“We were shown the play by them and then we made an agreement with those producers to partner with MCC if there’s a commercial transfer,” Telsey says.

As opposed to some not-for-profits, MCC is trying to make itself the primary commercial producer when productions transfer. “Many not-for-profits just license the production out to the commercial producers. We’re trying to create a trend where the not-for-profit owns its work and capitalizes on it, which will serve the theater as opposed to an individual producer.”

There are no absolute rules for dealing with commercial producers. Not only do the circumstances vary company to company, but from production to production at a particular venue. Although they are musicals, last season’s “Parade” was brought to Lincoln Center Theater by Hal Prince and Livent, whereas this year’s “Marie Christine” is entirely an LCT production.

At the Manhattan Theater Club, with its 27-year history of presenting new American works, the company has had big Broadway transfers with such works as “Ain’t Misbehavin’,” “Bad Habits,” “Mass Appeal,” “Crimes of the Heart” and “Love! Valour! Compassion!” Most recently, Cameron Mackintosh brought the Stephen Sondheim revue “Putting It Together” to MTC. “The cost of a musical is more expensive,” says artistic director Lynne Meadow. “He helped out with that.”

At MTC, the show starred Julie Andrews, but when it moved to the Mark Taper Forum in L.A. and then Broadway, Carol Burnett headlined.

“Commercial producers bring things to us to look at all the time,” Meadow continues. “We’ve been in a relationship with a commercial producer who wanted us to participate in ‘The Weir’ and make it part of our subscription season. I think our subscription audience made an impact on that show.” “The Weir” became one of the longer-running straight plays to debut in the 1998-99 season.

Generally, commercial producers “help out” not-for-profits with what’s called enhancement money.

“It happens all the time,” says Barry Edelstein, artistic director of the Classic Stage Co. “It is perfectly rational from an economic point of view. We can stage a production much less expensively than a commercial producer can.

“Their enhancement money can make our production much better. And if it’s a hit, the commercial producer has gotten the rights to the play much more reasonably than he would have in the commercial arena.”

In 1997, Douglas Carter Beane had an offer from a commercial producer to mount his then-new play “As Bees in Honey Drown” in a commercial venue. “But we wanted to produce it,” Beane says of the Drama Dept., where he is artistic director. “So the commercial producer gave enhancement money to the production, and got first refusal to move it.”

Beane says a similar situation now exists at the Drama Dept. with his just-premiered new play, “The Country Club.”

At the Vineyard, which has been producing new works since 1982, producer David Stone brought Becky Mode’s “Fully Committed” to the attention of artistic director Douglas Aibel, who recently presented the comedy’s world premiere. “He did not give us enhancement money,” Aibel says of Stone, “but he will have a crack at moving it to a commercial venue.”

In the 1990s, the Vineyard moved Paula Vogel’s “How I Learned to Drive” to Off Broadway with two commercial producers as associate producers, and also Edward Albee’s “Three Tall Women,” which had a team of commercial producers to manage the transfer.

The downside of all this transferring is that commercial producers sometimes can pull too many strings in the development of a new play.

“It’s very important, with work that’s delicate and in need of the proper development, that the not-for-profit theater maintain some degree of artistic control,” Aibel says.

“It’s our mission not to just produce new work but to support and protect the artist. We’re trying to avoid commercial pressures being foist upon an artist at that stage of the game, so you have to approach an enhancement situation very carefully.” One way the Vineyard ensures a degree of control is to give the playwright a contractual right of approval regarding outside producers.

At this point in the new season, it’s too early to tell what might happen with a slew of new American plays being readied at such other high-profile not-for-profits the Public, Playwrights Horizon and New York Theatre Workshop. Only this much is for sure: “Where we’re at it feels very much like the limelight,” says MCC’s Telsey. “Everybody is hungry to find a great new play.”