Officially, Jack Valenti, who has died aged 85, was merely the head of a trade organisation, but for nearly four decades he was known in Washington - and around the world - as Hollywood's influential ambassador and an international figure in his own right. He was also an aide to President Lyndon Johnson, and, in 1963, was in the Dallas motorcade when President John Kennedy was shot.
When Valenti became president of the Motion Picture Association of America (MPAA) in 1966, it was made clear to him that he would lobby for the major studios only under their direction. But the studio system was fragmenting and it was his dynamic energy and diplomatic skills that kept them together and consolidated their influence; it was a feat that increased the professional stature of the diminutive Valenti (he was just 5ft 4in). A 75th birthday eulogy on National Public Radio completely ignored his official title, referring to him only as "Hollywood's Jack Valenti".
During frequent trips to Europe, Valenti would stay at the embassies of US ambassadors while pursuing Hollywood's own foreign policy "with the authority to negotiate on its own terms with governments" as he grandly defined it. His vociferous insistence on Tinseltown's rights to unimpeded free trade nearly wrecked world trade talks (Gatt) in Geneva in 1993. Accusations of American cultural imperialism merely inspired Valenti to deliver lectures on the priority of freedom of expression.
He earned over $1m a year, lived in a seven-bedroom mansion in Washington with a private screening room, and dressed in tailored shirts and bespoke suits. But the Savile Row look ended at his trouser bottoms, from which peeked elaborately tooled cowboy boots, a legacy of his upbringing in Houston as the son of a poor Italian-American clerk. He had a pronounced Texan accent that added an unintended comical touch to his rotund speaking style and frequent quotations from the classics.
In his final years at the MPAA, as he moved into his 80s, his talents in the political and economic spheres were overshadowed by the American debate over Hollywood's declining taste and moral standards on screen, a topic he understood less well. His Democrat political instincts - honed when working for Johnson - always placed him in a free-speech defence, when many Americans began to believe, as one advocate put it, that Hollywood's violence and vulgarities had become a matter of public health. Eventually he confronted anti-Hollywood campaigns not just from Republicans, but Democrats too.
Valenti graduated from high school at 15 and worked in the oil fields to earn money to attend the University of Houston and later Harvard Business School. He spent the war as a bomber pilot, flying 51 missions over Italy and Germany and earning numerous combat medals. By 27, he was running the advertising department of the Humble Oil and Refining Co, and, at 31, had started his own advertising agency in Houston. In 1955 he met Johnson, then majority leader in the senate, and began working for him part time.
On November 22 1963, as press co-ordinator during Kennedy's Texas visit, Valenti found himself in the fatal motorcade. He talked his way aboard Air Force One, from where he checked the correct words for vice-president Johnson to utter as he took the presidential oath of office. The photograph of this event, with Valenti a small figure on the periphery, was one of two prominent pictures in his Washington office. (The other was of his best friend in Hollywood, Kirk Douglas, starring in the 1960 epic, Spartacus.)
Valenti remained at the White House until assuming the MPAA job, and within two years had established a new voluntary code of ratings. It replaced an increasingly unwieldy system with just five categories, from "general" to "restricted" with additional ratings of "parental guidance" for children.
After this, complex matters of trade, licensing, copyright protection, and latterly the internet revolution, preoccupied him. He was defeated at the Geneva trade talks and lost a fight to resist a television rating system for violent and sexual programmes during the Clinton administration. But he saved Hollywood hundreds of millions of dollars by outwitting the television industry in the early 1980s over claims to movie syndication fees.
Abroad, he was a tenacious and often successful fighter for retaining and opening markets to Hollywood entertainment. This made him an irritant in Europe with his incessant skirmishings against domestic film subsidies and quotas, and his implacable defence of US "cultural dominance". In Asia, he was relentless in hunting down pirating of Hollywood films. He also set up a Copyright Commission, which included the music and software industries, to prevent plagiarism on the internet.
He found time to write four books, including a 1992 novel, played golf with billionaire Warren Buffet, and on a visit to Britain in 1998 finally met his favourite actor, Paul Scofield, over tea at the actor's home. Valenti watched Scofield's 1966 Oscar-winning performance as the martyr Sir Thomas More in A Man for All Seasons dozens of times and could quote large portions of it verbatim. He always admired Britain, especially its actors and film-makers - except when he thought they encroached on Hollywood studio interests.
A popular after-dinner speaker, he wrote a classic on the craft, Speak Up With Confidence. It was first published in 1982 and 20 years later was updated and reissued.
Valenti announced his retirement from the MPAA in early 2004 after nearly 38 years. He is survived by his wife Mary Margaret, a former Johnson aide, whom he married in 1962, two daughters and a son.
· Jack Joseph Valenti, lobbyist, born September 5 1921; died April 26 2007
