Leslie Linder: Actor and theatrical agent who worked with Jack Lemmon, Rod Steiger and Peter Sellers

Leslie Linder was one of the most respected and successful theatrical agents during the boom years of British films in the 1960s and '70s. A big man of extraordinary energy and charm, Linder gave up his acting career in 1961 to join the talent agency, John Redway Associates, where he swiftly made an impact nursing the careers of young actors – including Sean Connery, whom he discovered in the chorus of South Pacific and insisted on signing despite his partner's objection to the actor's dirty fingernails.

When Peter Sellers, who had just won rave reviews for his role as Clare Quilty in Stanley Kubrick's Lolita, received a Hollywood offer he felt he couldn't refuse, he asked Linder to break the contract for his next film, a minor British comedy called Waltz of the Toreadors. Although Sellers was one of his agency's biggest clients, Linder refused to do it. Ten days before Toreadors was due to start shooting, Seller's withdrawal would have killed the project stone dead. "You'd put a hundred people out of work, Peter. You can't do it," Linder said. Sellers threatened to move his representation to the American agency, William Morris. Unflustered, Linder gave him the directions to the Morris office. Sellers backed down.

Linder's stubborn integrity and reputation for straight-dealing was well established by the time he opened the Redway office in Rome in 1964, where he continued to attract a dazzling array of some of the most talented actors, directors and writers for the productions Hollywood was setting up in Italy to take advantage of the lira-dollar exchange rate.

Although his mid-Atlantic accent made many of his clients believe he was an American, he was born on 31 August 1924 in North London, where his father owned a chain of confectionery shops. He was 11 when he was taken to New York on a visit, and stayed on with relatives for five years. He became an accomplished American football player and remained a dedicated sportsman all his life. Until a year ago he played tennis and worked out every day.

In 1940, he went to Canada and tried to enlist in the army. Turned down because of his age, he spent a year playing semi-pro American football before returning to England in 1942 and joining the Royal Armoured Corps. He was discharged in 1945 with the rank of captain in the Parachute Regiment.

With no idea what he wanted to do now that the war was over, he saw an advertisement in a copy of the News Chronicle he picked up on the underground offering government grants for ex-servicemen for the Royal Academy of Dramatic Arts. Although he had never acted in his life – "I was six foot two, had a flaming red beard, and I thought: why not give it a go?" – he applied, and won a place. Other students in the two years he was there included Adrienne Corri, Peter O'Toole and Laurence Harvey, who later became a friend and colleague. It was the start of an acting career that would take Linder back to New York in the golden age of American live television, where he worked with Jack Lemmon and Rod Steiger.

After 10 years in the agency business, in 1971 he joined Martin Ransohoff's Filmways company. His first film as a producer was 10 Rillington Place. Based on Ludovic Kennedy's book, it was the story of the serial killer John Christie, played by his friend Richard Attenborough, and the execution of the innocent Timothy Evans (played by John Hurt) for the murder of one of Christie's victims.

A committed campaigner for social justice, Linder found his greatest fulfillment in projects which expressed his own beliefs. As an anti-apartheid activist, he had met Nelson Mandela and Oliver Tambo before the former's imprisonment in the early 1960s, and produced Mandela, starring Danny Glover, for the BBC in 1987.

In the 1960s, together with Stella Richmond, and his friend and client, Wolf Mankowitz, he had brought the Ward Room, a moribund restaurant in Curzon Street, and planned to turn it into a place where his clients and friends would want to go. The journalist Logan Gourlay was not impressed. "This is a terrible idea," he said. "You'll lose your shirt. It's a white elephant." Linder called it The White Elephant, and it became the place to dine for Hollywood stars in London for 30 years. In the 1970s, with Lord Lichfield and the celebrity tailor Douglas Haywood, he opened Burke's restaurant in Mayfair, continuing the "lucky elephant" theme with the Cool Elephant, a jazz club, with Dudley Moore as resident pianist.

It was not until he was diagnosed with leukemia at the age of 80 that Linder thought of "taking it a little easier" – even so, he was the only man his doctor knew who continued to play tennis every day throughout his chemotherapy treatment. Zealously guarding his privacy, he avoided award ceremonies, declined interviews, and saw only old friends in the last decade of his full life. "I have a wonderful son, two terrific daughters, six grandchildren whom I adore, and a beautiful and loving partner [the former fashion marketing guru, Norma Quine]. What else do I need?" he recently told a friend.

Peter Evans

Leslie Linder, actor, theatrical agent and restaurateur: born Highgate, London 31 August 1924; married 1952 Dorothy Alison (separated 1971, died 1992; one son, two daughters); partner to Norma Quine; died London 16 January 2010.