Alan Sharp

Alan Sharp, who has died aged 79 of cancer of the brain in Los Angeles, was a novelist and a prolific screenwriter. Although he was born in Alyth, adoptive parents in Greenock, a Salvation Army couple, brought him up from an early age.

On leaving school at 14, he followed his stepfather into the local shipyards before moving to London around 1960. There, in 1963 to critical acclaim, he published his first novel, A Green Tree in Gedde. This was the first of a projected trilogy, and won the Scottish Arts Council Award in 1967, but only the second novel – The Wind Shifts –was published, in the same year. Sharp went on to demonstrate his versatility as a writer by having several radio and television plays produced in the UK, including The Long Distance Piano Player in the Play for Today series.

Contemporaries of his during this London period remember that his new-found literary success led to him becoming an articulate, charismatic, eloquent and larger-than-life character. But like many men with these attributes, he could also be difficult. It was in London that he met a couple of American film producers who financed a move to Hollywood around 1970, on the basis of a script of his called The Hired Hand.

During the 1970s, he wrote several well-received original feature films, including The Hired Hand (1971), Ulzana's Raid (1972), Billy Two Hats (1974), and Night Moves (1975). These films are regarded by many critics as classics of their genre, and featured actors of the calibre of Peter Fonda, Warren Oates, Burt Lancaster, Gregory Peck, Gene Hackman and Jennifer Warren. It was during this period that he met Harriet, who was to become his partner for more than 30 years, and subsequently his wife.

During the 1980s and early 1990s, he wrote mainly television films, of which The Osterman Weekend and Mission of the Shark: The Saga of the USS Indianapolis are probably the best known. Some observers thought that he had shot his bolt as far as feature films were concerned, but he proved them wrong with his superb 1995 script for Rob Roy. Subsequently, he wrote another half-dozen teleplays, before writing the screenplay for the idiosyncratic but heart-warming 2008 feature film My Talks with Dean Spanley, with Sam Neill and Peter O'Toole. His last produced work was the 2010 television mini-series Ben Hur.

However, he also wrote a screenplay for a feature film about Robert Burns, focusing on the Bard's relationship with Clarinda (Agnes Maclehose) to be directed by Vadim Jean and produced by James Cosmo – who apparently wanted to call this film Clarinda, but Sharp preferred Dancing in Armour. He was often heard to remark – and not entirely jokingly – that he could empathise with Burns's sexual chaos for, as a young man, he had led an equally turbulent, and not entirely blameless, life. The status of this project is unclear at the moment.

Further, in addition to those screenplays which were produced, Sharp penned a number of unproduced scripts, as well as uncredited rewrites, as is the lot of all professional screenwriters.

As a screenwriter, he was a consummate professional, highly regarded in the film and television industry by directors, producers, writers and actors alike. His film stories often evinced a metaphysical edge wherein issues of morality were debated: Ulzana's Raid, for example, is an anti-Vietnam War allegorical tale.

Amongst his fellow professionals, he was also admired for dialogue that fairly crackled, and imbued a strange authenticity to his Greenock man's take on the old west. He was characteristically modest about his successful output, which spanned more than 40 years, often referring to his work as "pastiche"– industry professionals know better. All in all, he was probably the most successful screenwriter in the UK and an inspired teller of film stories; it seems bizarre that Bafta did not honour him.

Latterly, he developed an interest in teaching screenwriting, both in the introductory University of Glasgow night-class, and at a masterclass level in New Zealand, where he retained a home on Kawau Island. He proved to be a born teacher.

He was gregarious, warm, witty, and a loyal, sensitive and most generous friend, possessed of a formidable enquiring intelligence and vast reading which he wore lightly. Despite his youthful excesses, he proved to be a devoted father and grandfather, definitely a family man. He enjoyed good food, drink and company, and retained a lifelong love of football, including the fortunes of Morton FC.

His long sojourn in the United States ensured an interest in conspiracy theories such as the death of Kennedy, the moon landing and crop circles, but his analysis of these events was always his own. And although he earned his living for many years in Hollywood, he eschewed both the conspicuous consumption and celebrity culture of tinseltown.

He is survived by his wife Harriet, and six children: Mike, Dan, Nola, Louise, Ruth and Minnie.