The Cambridge native is best known for his work on the TV series "Casualty," "Manimal" and "Falcon Crest," as well as in the 1978 Agatha Christie film "Death on the Nile." He also appeared in the West End production of "The Sound of Music" until it closed in February 2009.
His publicist, Max Clifford, told the BBC the actor died Thursday night in the arms of his wife, actress Susan George.
"No one could have fought this disease any harder than he did since being diagnosed four years ago," the British broadcaster quoted George as saying Friday. "He fought it with such strength, courage and belief. Last night, he lost this battle, and he died peacefully in my arms. To me, he was simply the best of everything, and I loved him with all my heart. He will live on in me forever."