Mariner Books, originally an imprint of HMH Books, was established in 1997 as a publisher of fiction, non-fiction, and poetry in trade paperback. Mariner is also the publisher of the Harvest backlist, formerly published by Harcourt Brace/Harcourt Brace Jovanovich. HarperCollins bought HMH in May 2021 for US$349 million. As of fall 2021, Mariner Books was listed as an imprint of HarperCollins. List of books published. The Hobbit by J.R.R Tolkien (1937) The Fellowship of the Ring by J.R.R Tolkien (1954) The Two Towers by J.R.R Tolkien (1954) The Return of the King by J.R.R Tolkien.
https://en.wikipedia.org/wiki/Mariner_Books