Helen Montagu, who has died aged 75, was an inspirational figure in the post-war British theatre, first as a vivacious general manager of the Royal Court and subsequently as an independent producer in the West End. She had an infallible nose for talent, and plucked a young Catherine Zeta-Jones from the chorus of the Drury Lane production of 42nd Street in 1986 to cast her as the take-over lead, Peggy Sawyer.
A stylish, no-nonsense Australian who was a dashing black-haired vamp for half her life and a stunning ash-blonde for the rest, she also had a gift for friendship spanning the entire range of the showbusiness elite. Meanwhile, she enjoyed an exemplary family life, unshakeably married since 1953 to the consultant psychologist Russell Willett, whom she met when both were students at Sydney University.
Helen Montagu was born in Sydney on April 21 1928, the only daughter of a bank manager. Her husband wanted to study at the Maudsley Hospital, and she wanted to train as an actress (there were no drama schools in Australia), so the young couple hitch-hiked to England. In London, she taught in Hackney and went to Toynbee Hall for classes in voice and movement.
She studied at the Central School and, after a period as a small-part actress and a shorter one as a radio interviewer in Canada, she was called in by George Devine at the Royal Court and offered the job of casting director in Sloane Square in 1964. Devine died soon afterwards, but as general manager of the English Stage Company at the Royal Court between 1965 and 1972, she was part of that theatre's second great surge.
Devine's successor, William Gaskill, elevated her to his general manager and inaugurated one of the most significant periods in British drama. Her outgoing character, unhampered by notions of snobbery, ensured popularity - or at least a fair hearing - with press and Establishment figures at a time when the theatre brandished an entrenched attitude stemming from its bravely innovative work and puritanical aesthetic.
There was controversy over Edward Bond's Saved in 1965, with its baby-stoning episode, and a sell-out production by Gaskill of Macbeth in 1967, with Alec Guinness and the French film star Simone Signoret. This period also saw the fruitful collaboration between the writer David Storey and the director Lindsay Anderson - John Gielgud and Ralph Richardson in Home was one unforgettable highlight; others included Glenda Jackson and Marianne Faithfull in Chekhov's Three Sisters, and the rediscovery of D H Lawrence as a major playwright.
With Gaskill, Helen Montagu supervised a significant incursion of the fringe theatre in their 1970 "Come Together" festival, and the playwrights Christopher Hampton and David Hare were given important premieres. Montagu left Sloane Square in 1972 and attempted to revive the fortunes of H M Tennent, the West End's most famous producing company, but this was not a happy time for her. She teamed up with Cameron Mackintosh in 1976 to produce Side By Side By Sondheim, a cabaret of that composer's songs presented by Ned Sherrin; the show established Stephen Sondheim in the British theatre.
And whether producing or simply cheering from the sidelines - "Hello, my daahling!" was never, in her voice, a phrase of affectation - she remained a much-loved figure to the end.
Helen Montagu died on New Year's Day after a stroke. She is survived by her husband and their four children.