A dozen Conan novels & fix-ups were
published in merkin mass market p/b by Lancer Books & Magnum/Lodestone/Prestige Books (not all by all of these loosely apparently linked last three), and in uk p/b by Sphere Books. In the messy aftermath of Lancer's banruptcy in 1973, it was determined that Sphere Books Ltd had the rights to continue publishing Conan books in the uk & (most of) the british commonwealth.
Lancer's original series numbering, also used by Sphere, was later changed by them, with Sphere following suit; subsequent books published by Berkley & later Tor Books in merkin mmp/b (some in large format trade p/b) were published in the uk by Sphere Books with series numbering running on from those first dozen or so, in the order in which they were published, through (circa) number 30;
i.e. series numbering is inconsistent, in both merkin and uk editions, and is no reliable guide to internal chronology.
The film novelisation of Conan the Barbarian was not initially so numbered by Sphere, though some later reprintings assigned it a place in the scheme.
Not all of the Tor Books pastiches had been published by Sphere Books by the time it was sold to Penguin Books, divested of its most attractive - to penguins - properties, and then sold on to, and absorbed by the bouncing (but insufficiently buoyant) czech, robert maxwell's MacDonald/Futura / BPCC publishing empire; Sphere Books disappearing both as a separate entity and as a publishing imprint.
It is possible that one or two reprints appeared - if so, i believe probably illegally, given what i understand of the terms agreed in the aftermath of Lancer Books'bankruptcy, and in the absence of the parties to these agreeing their variance - under MacDonald/Futura / BPCC's Orbit Books imprint.
Six of Tor Books' original Conan pastiche novels were published in uk p/b in Legend Books, Century-Hutchinson's Arrow Books' fantasy & sf imprint, later spun off as a separate company and then sold by the by-then owners, Random House uk ltd, to be absorbed into Orbit Books by their post-maxwell owners, Time-Warner uk and disappear as company and an imprint, the two Legend Books omnibus editions collecting these six novels as Conan Chronicles 1 & 2, being reissued as Orbit books - legally, so far as i am aware.
N.B. three different uk publishers have released books entitled Conan Chronicles; the contents of those published by Orion Books under their Gollancz imprint being of Robert E. Howard's original stories.