Is it permissible for a colleague working at an electronic publishing company to re-introduce books that have already been contracted with their author for publishing, by contracting with a publishing house, so that he receives a twofold remuneration for these books, knowing that the publishing rights belong to the author or the publisher?

The author's or publisher's right to publish and print books is not limited to once or twice. So, if he contracts with an electronic publishing company to re-print the book, that is his right, and the money he receives from it is lawful (halal (definition)); because copyright and publishing rights belong exclusively to the author without a time limit for the period of utilization.