Though not the one you're likely thinking of.
Solaris has purchased the reprint rights to Paul Kearney's first three novels: The Way to Babylon, Riding the Unicorn and A Different Kingdom, and will be publishing these as an omnibus in early 2014.
The status of Kearney's omnibus of The Sea-Beggars, which will include the brand-new third and concluding volume of the trilogy, Storm of the Dead, remains unclear.
These early novels of Kearney were different from his later work, which was historically-influenced epic fantasy. They featured people from the real world crossing into a fantastical one, with A Different Kingdom being more of an Irish take on Robert Holdstock's Mythago Wood (without being derivative of it). The three books are also independent of one another and are not part of the same series.