The two comic creators have had a number of ownership disputes over the years concerning characters Gaiman had created for Spawn in the early 1990s, including Medieval Spawn and Angela.
The ruling states that Macfarlane's recent characters Dark Ages Spawn, Domina and Tiffany are simply variations on the earlier Gaiman creations and that MacFarlane had to pay Gaiman half the money earned from the sales of the three characters.
Comic Book Resources reported that the judge disagreed with Macfarlane's assertions that the three characters had not been influenced by Gaiman's creations.
The dispute between the two has been ongoing for a number of years, with Gaiman remaining unpaid for his involvement in the characters' creations, despite owning a 50% share in them.
"Much as the defendant tries to distinguish the two knight Hellspawn, he never explains why, of all the universe of possible incarnations, he introduced two knights from the same century," CBR reports Judge Crabb as saying. "It seems far more than coincidence that Dark Ages Spawn is a knight from the same century as Medieval Spawn."
Gaiman and McFarlane were previously involved in a lengthy dispute over ownership of the character Miracleman until Marvel Comics purchased the rights last year.