Roger Hancock: Agent who guided many showbiz careers and protected the legacy of his brother Tony

Following work as a stage manager in the theatre and a senior manager role at the new ITV companies Tyne Tees and Southern, Roger Hancock became an agent who guided the careers of many writers and performers, with a roster that was the envy of his rivals. Highly respected and known for his warmth, congeniality and sense of humour – a "peopleaholic", as Barry Cryer called him – he was also a perfectionist and astute businessman who had great foresight and could be abrasive when he felt it was called for.

After a short stint as general manager at Associated London Scripts, he set up Roger Hancock Ltd in 1961. Among the first clients was his older brother, Tony, the actor who had enjoyed a long run on both BBC radio and television in the legendary sitcom Hancock's Half Hour. The previous year, a chain-smoking, nervous-looking Tony had been very self-critical in a Face to Face television interview with John Freeman. "It was the biggest mistake he ever made," Roger reflected later. "I think it all started from that, really. Self-analysis – that was his killer."

In 1961, Tony dropped his comic foil Sid James, concerned that they were coming to be seen as a double act, and retitled his sitcom Hancock, in a series that featured two classic episodes, "The Radio Ham" and "The Blood Donor". The first included in the cast Annie Leake, Roger's wife, as the neighbour complaining about the noise as Tony is trying to help a yachtsman following a mayday call.

Around the time the actor left his long-time agent Beryl Vertue, he also dropped his sitcom writers, Ray Galton and Alan Simpson, and planned to switch to ITV. The resulting series, Hancock (1963), failed to reach the same standard and was followed by the star's depression and alcoholism, which culminated in his suicide in 1968.

In between, Roger had found Tony's behaviour so impossible that he parted company from him as an agent, partly so that any business disagreements would not ruin their relationship. Following Tony's death and as beneficiary of his will, Roger was responsible for protecting the reputation of the man regarded by many as a comic genius. One way of doing this was to ensure that the ITV series was never repeated or released on video or DVD.

Roger Hancock was born in Bournemouth in 1931. His parents owned the Durlston Court Hotel, but his father, Jack, who also worked as an amateur comedian, died three years after Hancock's birth, in 1934. Roger and Tony's elder brother, Colin, was a pilot officer during the Second World War who went missing, presumed dead, over the Atlantic. After attending Tonbridge School and the Loomis Institute, in Windsor, Connecticut, as an exchange student, Roger did national service in the Army's Intelligence Corps.

With Tony already on stage, he headed in the same direction but was less keen to appear in front of an audience. He worked backstage at the Players Theatre, Charing Cross, where he met the actor Clive Dunn, who became a lifelong friend. When Dunn was asked to direct a summer season at the Little Theatre in Southwold, Suffolk, he gave Hancock similar work. Then came a return to the Players Theatre as stage manager, where Hattie Jacques introduced him to his wife-to-be. This was followed by the same role at George and Alfred Black's theatres, including the Adelphi, in London's West End. He was also part of the brothers' Tyne Tees television consortium that successfully bid for the ITV North East franchise and started broadcasting in 1959.

Switching to the role of an agent at Associated London Scripts, he represented stars such as Peter Sellers, Spike Milligan and Michael Bentine (of the Goons), Eric Sykes, Jimmy Edwards and Frankie Howerd. Some of the writers and performers, who also included Galton and Simpson and Johnny Speight, were among those who helped to shape radio and television comedy.

When Hancock set up his own agency he signed up Cryer on a handshake, and the writer remains on its books. Others enticed included the Dad's Army writers Jimmy Perry and David Croft, Willie Rushton, the Monty Python team and the Goodies.

In 1968, the writer Terry Nation, who contributed to the Hancock ITV series, joined Roger Hancock Ltd after leaving Associated London Scripts. He had created Doctor Who's Daleks, which ensured years of royalties, and then created another cult sci-fi series, Blake's 7 (1978-81). Hancock thrashed out a deal for merchandising rights before the new creation hit television screens and, after Nation's death, negotiated another that allows for the making of an as-yet unproduced Blake's 7 revival. Another client still with the agency is David Renwick, writer of the sitcom One Foot in the Grave.

One of Hancock's few wrong judgements came in the early 1960s when he went to see a Rolling Stones concert on Eel Pie Island, Twickenham, and rejected the idea of taking them on because "they looked too scruffy".

In 1979, Hancock also started a successful period in which he sold British programme formats, including Jim'll Fix It and Antiques Roadshow, to the US. Another was for the sitcom Dear John, written by John Sullivan, the Only Fools and Horses creator whom Hancock was quick to sign up. (Sullivan and Hancock died on the same day.) Formats he took in the opposite direction included Game for a Laugh, Wheel of Fortune and Catchphrase.

After 1996 Hancock eased off work before retiring completely in 2001 and handing over the running of the business to his son Tim. A cricket enthusiast who ran his own celebrity team for many years, he spent his retirement in Brighton and enjoyed salmon fishing. His other son, Toby, is a photographer.

Anthony Hayward

Roger Thomas Hancock, agent: born Bournemouth 6 June 1931; married 1955 Annie Leake (two sons); died Brighton, East Sussex 23 April 2011.