Cleverly edged out Bellew when the pair met for the WBO light-heavyweight title in October 2011, but their fierce rivalry has continued since then due to regular disparaging comments from each fighter.
"We are almost there," Hearn revealed to reporters. "Having been originally set for December 6, we are now finalising a new date and venue and I hope to have the deal tied up this week.
"This is a wonderful fight – two great fighters with a genuine rivalry that will keep fans on their toes in and outside the ring. I can't wait for this fight, and of course the build-up."
The winner of any potential bout is likely to be in line for a world title shot.