''It's a strange trend because many of the books are hardly great literature, but youngsters, especially, see the movie and then find the English book easier to follow.'' Ms Wong said that Michael Crichton's Jurassic Park and John Grisham's The Firm were their best-sellers this summer, ''and we're talking tens of thousands of copies''. What she finds more difficult to fathom is why someone would want to read something like Indecent Proposal after seeing the film.

Distributor Mohan Mirchandani of Far East Media believes the movie tie-in business has been building up over several years. He remembers books of the Superman movie selling well in the late 70s. ''It's the publicity that's grown bigger,'' he said. ''A book's sales performance depends entirely on the movie's success. Many movies come and go and we just sell a few books.

''But a film like Jurassic Park, where the publicity generated is huge, increases sales dramatically. The book was already selling well before the movie arrived, but afterwards it went from hundreds a week to thousands.'' While there's no record of overall sales for individual books in Hong Kong, an example from the US of how a film can revive book sales is Edith Wharton's book The Age of Innocence. Written 72 years ago, it has just been made into a film, directed by Martin Scorsese and starring Daniel Day-Lewis, Michelle Pfeiffer and Winona Ryder.

The Collier paperback sold 12,000 to 15,000 copies last year. A new edition to coincide with the film has sold 100,000 copies in the past few months and the company now has 400,000 more in bookstores across the country.

Christina Macphail, export sales manager of publisher Little Brown described the book tie-in industry as ''huge'' - if erratic.

''We try to go for dead certs,'' she said. ''But it doesn't always work. They tend to be either phenomenally successful or an absolute dog.

''We've got The Last Action Hero which should have been a winner, but flopped everywhere. Like Hollywood, we hoped that it would do better in places like Hong Kong, but it just didn't happen.'' Timing can also be difficult since most movies come to Hong Kong before they open in London and tastes differ from country to country. ''I bought Dragon [the book of the Bruce Lee biopic] with Hong Kong in mind, thinking it would be huge there,'' said MsMacphail. ''But it just fizzled out after a few weeks.'' Another problem peculiar to the territory is the uncertainty of whether a particular film will be released here at all.

PAL's Ms Wong said: ''With Howards End an edition was put out sporting a still from the movie on its cover. But we're left wondering if the film's going to come to Hong Kong at all, despite cinema promos saying it would.'' Other quality movies can prove surprisingly successful, however with a knock-on effect for book sales. Hong Kong's summer sleeper, the Mexican movie Like Water For Chocolate is still packing audiences in at the Cine-Art House after nearly six months.It's based on Laura Esquivel's original novel in which a young woman expresses her love through her exquisite cooking.

''We had [the book] Like Water For Chocolate in-store in January and it hardly moved,'' said T Li, manager of the Hong Kong Book Centre. ''Since the film there's been big interest. Some people want to read the story, but a lot of them want it for the recipes. The same happened with Fried Green Tomatoes last year.'' The major publishers have to make their decisions on which movie books to bid for early on in the film-making process. Penguin's vice-president (film and television) Sue Berger is now based permanently in Los Angeles so that she's on the spot to read scripts while the movie is still being made. She will assess the probability of a good book spin-off from the script, the actors involved and - if they're famous enough - the director.

''Some films like Batman or Terminator, lend themselves to merchandising, others to books - usually more serious subjects where you want a proper, adult novelisation done.

''As far as we're concerned there are three kinds of tie-ins. The first is books that you already own, like Malcolm X or Sliver , where you just put on a new cover and do a joint marketing drive with the studio.

''Second is the book based on the movie, like Indecent Proposal. And the third, we call a novelisation, where we turn a screenplay into a novel.'' From the point of view of the author this mania for book tie-ins can only be good news. The mammoth success of Jurassic Park has not only kept that book in the bestsellers' lists all summer, but has prompted the publishers to dust off Michael Crichton's early works and reprint them.

It has also helped sales of Mr Crichton's last book, the controversial Rising Sun which should get another boost when the film - starring Sean Connery and Wesley Snipes - comes to Hong Kong next year.

On top of that Warner Bros has offered the author US$3.5 million (HK$27.06 million) for feature film rights to his unfinished new book.

As for the books themselves, the classics are generally just given a new cover, the prose left unchanged. But problems can arise in translating into book form a movie whose main attractions are breakneck action sequences, special effects and pyrotechnics.

The authors' descriptive powers are severely stretched early on in The Last Action Hero when Arnie Schwarzenegger's character Jack Slater is described as ''a six-and-half-foot mountain of a man, his shoulders as broad and hard as a car bumper''.

And later: ''The most peculiar thing about Slater - his heavy Austrian accent - had never been remarked upon by anyone who knew him.'' Well that gets rid of that little credibility hiccup.

As for romance, the best advice there comes in Super Mario Bros - the ultimate in tie-ins since it's the book of the movie of the cartoon of the computer game.

Plumbers Mario and Luigi are discussing dating. Mario advises: ''The first thing you gotta do is tell her what your are. Even if a girl is a princess, their toilets clog up too you know.'' It's a literary classic.

It's not all banal though. In Cliffhanger Sylvester Stallone's character Gabe Walker finds time to dabble in existentialism: ''You can't change what you are. So, you might as well just be it.''