However, I should note that copyrights and trademarks are two very different things; any attempt by an author to make money by selling stories using copyrighted characters (such as those in LOTR) would likely be sued for infringement, which does not require that any trademark exist in the character names, only that the new work is a "derivative work" in a copyright sense because it uses things from the original work. However, simply using a character name without copying anything else from the literary work wouldn't itself be a copyright violation, as names can't be copyrighted, only the entire concept of the character (words, images, etc.).
There have been litigated cases where somebody has only a copyright but not a trademark, or vice versa, which affects what things are protected. (Obviously, the strongest rights are when the author has both a copyright and a trademark.) If the copyright to famous characters like Mickey Mouse eventually expires (it's been delayed a few times by copyright term extensions, but may run out someday anyway), Disney would still own trademark rights to the character's name and image, which would mean that somebody could sell copies of "Steamboat Willie", or make new cartoons derivative of it, but couldn't actually sell it with packaging or advertising that uses trademarked Disney elements like "Mickey Mouse". Confusing, huh?
Conversely, DC Comics bought the copyrights to the character Captain Marvel from Fawcett in the 1970s (after having stopped Fawcett from publishing it in the 1950s due to alleged copyright infringement on DC's Superman), but by then Marvel Comics already had a different character named Captain Marvel and owned trademark rights on the name, so DC was put in the position of owning copyright on CM but not trademark rights; their solution was to publish a comic named "Shazam!" that featured the character Captain Marvel in it, but didn't use the latter name in a trademark sense (they're prohibited from mentioning that name on the cover or in ads).
