The Understanding, the first full production by the nonprofit Colleagues' Theatre Company, a professional troupe devoted to presenting plays about "the mature life experience," will end its extended run, Feb. 6 at the Neighborhood Playhouse in New York City.

Colleagues opened Angela Huth's domestic drama, The Understanding, Jan. 13, following a Jan. 12 preview. It was originally scheduled to close Jan. 31, 1999 at the off-off Broadway venue.

Formed by actress Catherine Wolf in 1995, the company had focused on public readings and fundraisers prior to the selection of this month's official first full staging. Huth's Understanding was originally produced in London in 1982 starring Ralph Richardson.

The company's mandate is to explore the world of people over age 50, producing director Wolf told Playbill On-Line. "I was going to many auditions and seeing myself 9,000 times," she said. "There was a great need for a theatre in which women and men have plays where they're not just playing (grandparents)."

Wolf said she and her colleagues want to produce plays -- new and classic -- "about what happens to people as they get older." The 58-year-old actress said, "I've found I'm so much more interesting as I get older, and nobody thinks about that. There's been so much done about younger folks..."

Fundraisers, including a concert by Julie Wilson in spring 1998, have helped support the company, which also sponsors a new play competition and an apprentice program for young people. This year's apprentice, who receives scholarship money, is Sharika Niles, 18. She will stage manage The Understanding.

Harlene Goodrich's Light Under the Door was the first new play to be selected and read by the troupe, Oct. 19, 1998.

"The mature person who has been in the business as long as I have owes something to the business," said Wolf, who has been acting since age 11 and appeared on and Off Broadway, in TV, films and regional theatre.

Colleagues' The Understanding is a U.S. premiere. The play is set in a London drawing room where three sisters live in comfort with one sister's husband. Elowyn Castle directs.

The cast includes Broadway, TV and film actors William Cain, Mary Fogarty, Elizabeth Parrish, Wolf and Nile Lanning as the young woman who changes the sisters' world. Cain received an Emmy Award for "Separate But Equal." His stage credits include Young Man from Atlanta (with Rip Torn), A Delicate Balance (with Rosemary Harris), The Heiress (with Cherry Jones), A Streetcar Named Desire (with Alec Baldwin and Jessica Lange), Mastergate and The Boys of Summer (with George C. Scott).

Fogarty, who created the role of Ouiser in Steel Magnolias, has appeared in the Broadway productions of Joe Egg, Of The Fields Lately, Watch On The Rhine and The National Health as well as in national tours of The Secret Garden and Wonderful Town.

Parrish created the role of Jacqueline in Broadway's La Cage aux Folles and played Off-Broadway in Little Mary Sunshine, Cindy and Riverwind.

Wolf played Mrs. Birling on Broadway in An Inspector Calls and also appeared on Broadway in The Innocents (with Claire Bloom) and Otherwise Engaged, both directed by Harold Pinter. Her Off- Broadway work includes Beau Jest, Cloud Nine, I Can't Keep Running in Place and The American Plan.

Lanning was seen in the Lincoln Center Theater production of The Sisters Rosensweig and in Pericles at the Public Theater, as well as Off Broadway's A Shayna Maidel, First is Supper and Pigeons.

Playwright Huth is a British novelist and TV journalist whose eighth novel, "Land Girls," was recently made into a film. Her latest book is "Wives of the Fisherman." She has also written two plays (including The Understanding), three collections of short stories and plays for radio and TV. After the production on London's West End, The Understanding was produced for television.

Director Castle has directed for the National Shakespeare Company, American Renaissance Theatre and the Hedgerow Theatre as well as directing Cowboy Mouth at the Dubrovnik Festival in Yugoslavia.

The Neighborhood Playhouse is at 340 E. 54th St. (between 1st and 2nd Avenues). Tickets are $12. Call (212) 362-0312 for benefit information, or (212) 279-4200 for regular performances.

-- By Kenneth Jones