It took some quick thinking by Mike Kaplan to reassure the 2001 director that his masterpiece was in safe hands. Here, he recounts the rocky start of a long friendship

I was the resident longhair in the publicity department of MGM when I first met Stanley Kubrick, in April 1968. I had spent the previous four days canvassing the befuddled media, who were trying to grasp his new film, a non-verbal epic called 2001: A Space Odyssey, and MGM's executives were in fear about the prospects of their most expensive film to date and, consequently, their future.

Roger Carras, Kubrick's promotion executive, was taking me to meet the great man to explain to him why the film was near unanimously misunderstood. It was being presented as "an epic drama of adventure and exploration", and many were expecting a modern Flash Gordon. Instead, Kubrick had created a metaphysical drama encompassing evolution, reincarnation, the beauty of space, the terror of science, the mystery of mankind. The campaign had to be reconceived and repositioned - an impossible task unless Kubrick, who had complete control of his work, could be convinced this was vital to save his film from impending disaster and devastating reviews.

We were in the midst of the 1960s youth revolution. Friends in the underground press had already seen 2001 several times, exhilarated by his film-making, some nicely stoned. After my first confused reaction, compounded by false anticipation and intense company pressure, I walked out of the second screening elated, knowing 2001 was an experience challenging conventional movie audiences and traditional critical values.

And so Roger took me to the projection booth of Loew's Capitol Theatre in New York on the night of the movie's premiere. The Capitol's inner lobby was decorated with a fanciful garden created for MGM's previous roadshow attraction, The Wonderful World of the Brothers Grimm. As Roger and I crossed the fairytale bridge that led to the door of the projection booth, the incongruity of the atmosphere and my trepidation at finally talking to Stanley Kubrick was dizzying. My stomach was in knots.

He had just gone through the red-carpet frenzy - the last time he would attend one of his world premieres - and was checking the technical state of the Cinerama equipment. The "Dawn of Man" sequence had ended as we entered the large booth. He was standing casually next to one of the massive projectors, bow-tie undone, dinner jacket opened, his editors behind him.

"Stanley," Roger said buoyantly as we approached, "this is Mike Kaplan, whom I told you about." I reached out to shake his hand. Kubrick kept his in his pockets. The tension was palpable. I was the potential enemy in his den; my sincerity irrelevant. There would be no handshake. It was an existential confrontation.

His laser-like eyes locked mine: "Why doesn't Pauline Kael like my movie?" My mind raced. I had been nervous enough rehearsing what to say. He was famous for hustling chess games in his youth and had made a bold, surprising first move. Despite Roger's preparation about my passion for what should be done, this was his test of what I should know. Forget this upstart and his theories. Kael, the film critic of the New Yorker, was the most influential critic of the time.

Kael, however, wasn't a contact of mine. I had enough to keep up with the newspaper, broadcast media and wire services which were my purview. I read Pauline infrequently; found her analysis invigorating when I agreed with her and condescending when I didn't. I favoured her counterpart on the opposite side of the critical spectrum, Andrew Sarris, who had championed the auteur theory of film criticism in America and reviewed for the Village Voice, the New York alternative weekly. These were the days when critics held their opinions close to their chests and never saw a film more than once. From the brief message received by Joanna Ney, my close colleague and Kael's contact at MGM, and from the expression on the face of writer Dick Albarino, a friend who had accompanied Pauline to the first screening - and who was sworn to secrecy about her reaction - it was apparent she was going to be brutal. But no one knew specifics.

I felt the fate of the film was in the heavy air holding Kubrick's question. My answer had to meet his challenge. Perhaps a minute elapsed. Triggered by a survival instinct from some deep memory recess, I countered, "She thought The Bible was the best movie of the year." Our eyes didn't move but his body shifted slightly. It was my acknowledgment. We talked for the next two hours through to the end of the film and watched the mystified charity audience file out. Then we shook hands.

It was the beginning of an enduring friendship and my most commercially successful professional relationship. What cemented it was a marketing tactic that initiated the turning of 2001 into a cultural phenomenon. Besides Kael and Sarris, the major critical voices who could affect a film's success were the New York Times and the bright and bristling Judith Crist, the most widely known critic in the country, who reviewed for the New York Herald Tribune, the Today Show, the highest-rated morning television programme, and TV Guide, the country's largest circulation magazine. No critic ever had a larger audience.

Crist, a long-time supporter of Kubrick, was negative, reflecting the opinions of her newspaper colleagues who thought 2001 long, boring and impenetrable. The New York Times had named a new critic at the beginning of the year, Renata Adler, a novelist of note, whose film tastes were still unknown. (She would shortly compare the monolith to a Hershey chocolate bar.) Kael was on the attack and Sarris, whose views could signal an alternative force to marshal, would appear last. We were down three with one unknown. It was desperate.

Then, the unexpected. The Christian Science Monitor, the highly respected national newspaper based in Boston, published an elegantly designed full-page essay by John Allen, declaring the film a masterpiece with Kubrick reinventing the medium. This was the breakthrough, coming from a distinguished newspaper with substantial weight to balance the establishment consensus. Combined with a bubbling movement from the counterculture media, and the near-unprecedented second review by Newsday's Joseph Gelmis reversing his negative opinion within days of his first (only Newsweek's Joe Morgenstern had ever done this previously with his Bonnie and Clyde switch), the Monitor piece could refocus the film's future.

When the film came out, Stanley set up an office in the conference room on the 26th floor of the MGM building. Tearsheets of ads and reviews from every publication lined the walls. The Monitor essay had to be reprinted immediately, as an ad in the following Sunday's New York Times (Adler's weak review had just appeared) and for insurance sake, in the next issue of the Village Voice, in case Sarris was negative. Most importantly, it had to be read as an editorial; it could not look like an advertisement. The only commercial information would be a discreet line at the very end stating "2001: A Space Odyssey is showing at Loew's Capitol theatre."

Stanley got it immediately. Our plan was that I'd make the case and he'd play back-up if necessary. My boss bought the concept; there was nothing to lose. Business was well below average for a major release. And I was the film's designated point man, having Kubrick's trust. Advertising layouts were ordered immediately. But when the mock-ups arrived, I was shaken. Instead of an editorial look, the Monitor reprint was contained within the standard corporate information: MGM credits and the distinctive unfolding Cinerama logo fought the copy. It was too radical to remove the studio's corporate identity. The intended impact would be lost.

Stanley made his move. Privately, he went to the studio bosses to talk about the film's future openings, saw the mock-ups, and walked out with the layout we wanted - his calm logic prevailing. The advertising agency also delivered with placement. On Sunday, the piece appeared opposite the New York Times' main film page, making it look like a two-page editorial spread. There was nothing stating it was a paid ad. On Thursday, it ran opposite Sarris' lengthy negative review in the Village Voice. The campaign to turn the tide was engaged.

During the next four years, from the release of 2001, through its relaunch a year later with my "Ultimate Trip"/Starchild campaign, and the release of A Clockwork Orange (Stanley had asked me to leave MGM to work directly with him), we talked and strategised film distribution daily. We remained in close contact afterwards, watching Barry Lyndon with the American ratings chief in the large Shepperton screening room with his newly completed print; I visited the set of The Shining and later tried to persuade him to change the ad and slogan; I called him after seeing Full Metal Jacket to say I broke down at the visceral impact of the graveside scene, because my mother had died months before (he said, "There's nothing worse; it's like being hit in the head with a sledgehammer"). From then on periodically - I'd get a call and we'd speak for an hour or more as if it were yesterday.

Our last conversation was in 1994. I was at the Edinburgh festival, where Luck, Trust & Ketchup, my documentary about Robert Altman, was being shown. I had sent him a copy and was eager for his thoughts. He said it was "very good" then quickly moved to The Whales of August, which I had produced a few years before. "Who directed it?" he asked. (I knew he knew.) "Lindsay Anderson." "Oh, yes, I knew it was a good director. How did it do?"

It had been badly distributed, except for Japan, the only territory that followed my marketing campaign, where it played for a year and a half in Tokyo. He was intrigued and then described in detail how for Full Metal Jacket he had changed the way films were announced and released in Japan. Instituting new distribution methods fascinated Stanley as much as film-making, which he also called "an exercise in problem solving".

Next Friday, the American Academy of Motion Picture Arts and Sciences and the British Film Institute will present a joint tribute to Kubrick at BFI Southbank, hosted by Malcolm McDowell. At the same time, in the same building, Never Apologise, Malcolm's tour de force celebration of Lindsay Anderson, which I directed, will be showing.

More than anything, I'd be eager for Stanley's thoughts, to hear his coy chuckles, and to have another long, creative dialogue on the art of making and marketing movies.