There are a couple of cases of the original author re-writing hs book in the wake of a movie so hat it more closely resembles the film. Martin Caidin rewote Marooned after the film so that his Mercury-era space drama resembled an Apollo-era spaceship.
And Peter Bryant’s novel Red Alert was rewritten by him (under the name Peter George) as Dr. Strangelove: or How I learned to Stop Worrying and Love the Bomb.
I just thought of another noted SF author who did one – Robert Heinlein wrote a sort-of novelization of Destination Moon to coincide with the film’s release. He, of course, wrote the screenplay, which was, in turn very loosely based on his first juvenile novel, Rocket Ship Galileo.
I’ve read them occassionally, just for the hell of it-I like to read more than I like to watch movies, actually. But the only ones I really crave are the novelizations for the Star Wars movies.
One of the weirder novelizationists (?) has got to be Donald F Glut. He did the novelization of The Empire Strikes Back, which is the only one he has done (that I know of). It’s his other wrting that’s fascinating and weird:
Scholarly books on Vampires (published by Scarecrow Press)
The Dinosaur Dictionary (I’ve seen it on sale at the American Museum of Natural History)
The Dinosaur Scrapbook (filled with dd reproductions of dino memorabilia. I didn’t know anyone besides me knew of this stuff)
A series of not-great novels based on Frankenstein, the Mummy, etc.
Sociallyresponsible soft-core porn comics, like Fanta
Harder-core poern comics, like [BRocketship SM** (I kid you not)
He’s alsp appeared on the VHS compilation Dinosaurs.
The guy’s had a heck of a career. I still woner how he talked them into letting him do the Star Wars noveliation.
The king of novelizations has to be Alan Dean Foster. Here’ as complete a list as I can think of:
Star Trek Logs (novelizing the Star Trek animated TV series)
**Dark Star
Star Wars
Outland
Alien
The Black Hole
The Thing
Clash of the Titans
Krull
The Last Starfighter
Starman
Aliens
Alien Nation
Alien III
**
Oh weird, I was just wondering about this. I just can’t imagine feeling very satisfied or creatively fulfilled working as a, uh, novelizer. I bought a copy of Nightmare on Elm Street (I think there are a couple of them in there) just for the kitsch factor. I’m not sure I could ever bring myself to read it.
Some more SF novelizers:
George Alec Effinger wrote novelizations for the Planet of the Apes TV series.
Timothy Zahn and Kevin J. Anderson wrote novels based on Star Wars.
S.M. Stirling wrote some Terminator novels.
To be quite honest, I consider the entire Star Wars series of books to be nothing more than novelizations. But I’m pretty much of a snob that way. 
It depends on how you approach it. Take the novelizations of the two Spider-Man movies (both by Peter David).
The first one is a straightforward adaptation of the script, with some small backstories added to try and give a little more meat to the story.
The second one includes entire scenes, characters, and dialog that aren’t even remotely in the film, to show more depth to the main characters that the movie doesn’t even approach.
Yeah, if your approach to novelization is to just parrot the script verbatim, there’s little creative satisfaction involved. On the other hand, if you use the novelization as an opportunity to add stuff to the story that the movie can’t capture (time is a precious commodity in film, but words are easily available in writing), then it can be a satisfying challenge.
My understanding is that their contracts are similar - flat fee and they need to be vetted by corporate. I suspect Star Trek novels are similar.
I saw Foster giving a talk at a con once and someone asked him about his novelizations. He said that doing them got his name known to publishers; that he could then go in with a novel of his own and say “I’ve sold x thousands of copies of my books” and have a better chance of getting his own stuff published.
I suppose the all time classic must be J.M. Barries novalization of his own play * Peter Pan, or The Boy Who Wouldn’t Grow Up*
Yes . . . A really egregious example: When Kenneth Branagh’s Mary Shelley’s Frankenstein (purportedly more faithful to Shelley’s seminal SF novel than any film adaptation to date) came out, it was shortly followed by a novelization, titled Mary Shelley’s Frankenstein but not, needless to say, written by Shelley.
I remember a Phil Foglio cartoon from the D&D zine The Dragon: It’s about what to do if you’re an SF author whose book is being made into a movie. (Basic instructions: Demand payment in cash. Go to the California state line and have the bag of cash tossed over the border to you. Boil the bag before opening it. HAVE NOTHING MORE TO DO WITH THE MOVIE.) In one scene, a producer, sitting in an office with a big Dune poster on the wall, is leaning back in his chair and talking on the phone: “But Frank! Sweetie! Alan Dean Foster does all our novelizations!”
I don’t think I’ve read a film-novelization since the first Star Wars was novelized.
Those don’t count – they’re set in the same fictive world as the first two movies, but not adaptations of their plots. (I was really surprised, by the way, when T3 came out and it was not an adaptation of one of Stirling’s novels – I just assumed he was working under an arrangement with the studio, reversing the usual order by writing the novel before the release of the movie.)
One of my favorite reads in grade school was the book version of Back to the Future, those you got from Scholastic. It had pictures from the movie and all!
Relatedly, I hate when a movie is based off of a real book and they reprint the book but then the cover is a still from the movie. Argh, I hate that! I just feel the unwashed masses don’t realize their was a book before the movie. But then I guess it is good they are reading. (Or those books that have "Oprah’s Book Club stamped on it. At least I know to avoid it.)
My brother cannot think of the example that pissed us off just right now. But he does think that the Bible should replace the cover with a still from The Passion.
I wonder if they are going to come out with novelizations of the Lord of the Rings movies - if they do, I hope they throw in some catgirls. Or better yet, ninja catgirls. 
(Let’s see who gets that reference.)
He also wrote a “sequel”, Fantastic Voyage II. Interesting book, as I recall, but it’s been forever since I read it. I do remember, though, that not only is it not a direct sequel to the original, but it takes place in a world in which the events of the first book (and movie) never happened. So, I guess it’s more of a “remake” than a true sequel, despite its title.
If Dean Koontz’s The Funhouse is better than the movie, that must have been one shitty movie. I like a lot of Koontz’s stuff, much to my embarrassment, but I thought The Funhouse stank like a steaming pile of manure. You’re right, there was quite a bit of backstory there, but it was so poorly written. Even stuff he wrote before that (like Whispers) was better, even with his annoying tendency to inject his politics into the storyline.
Or give the Corsairs of Umbar some speaking lines: “Aaar! ‘Tis Elendil’s heir, blister me bollocks if it ain’t! An’ he’s at the head of an spectral army, splinter me sphincter! Damn rot and blast me eyes! Mr Bones! Break out the rum an’ cutlasses, an’ we’ll shiver their livers, pox take me else! Aaar!”
On the subject of S M Stirling, another faded cyberpunk luminary, Pat Cadigan, is also doing novelisations now - of Jason X.