^{Inspired by the comments on this question.}

J.R.R. Tolkien sold the rights to film adaptations of The Hobbit and The Lord of the Rings to United Artists in 1968 or 1969. Although he retained enough creative control at first to veto the Beatles' proposal to make an adaptation of The Lord of the Rings in the late 60's, it seems that he (and later, his estate) had little or no input in further attempts to make movies based on these two properties.

Since Tolkien died in 1973, his estate has done what it could to protect its property, even suing Middle-earth Enterprises, Warner Brothers, and New Line Cinema in 2012 for making casino machines and video games using the likenesses of Tolkien characters.

And in Tolkien's will, he named his son Christopher as his "sole literary executor", with authority to revise, edit, and publish J.R.R.'s other works. He has done so, releasing several previously unpublished books written by his father - The Silmarillion, Unfinished Tales, and The History of Middle-earth, to name a few. But I'm asking about adaptations of J.R.R. Tolkien's writing, not Christopher's publication of his father's previously unreleased writing.

##Has the Tolkien Estate - as opposed to Tolkien himself - sold any sort of rights to adaptations of any of Tolkien's works?