Piven said his illness meant he could not "get my lines out"
No agreement has been reached after producers of Broadway play Speed-the-Plow filed a grievance against Jeremy Piven over the actor quitting the show.
The Entourage star left the play in December after his doctor said he was suffering from mercury poisoning.
Representatives of actors' union Equity and a Broadway producers' association failed to reach a unanimous decision.
Piven told the New York Times after the hearing that his illness stemmed from eating fish twice a week for 20 years.
He told the paper that reports that he became ill because of eating too much sushi were untrue.
"I've never missed a day's work or a rehearsal in my life," he said.
He said he had tried to work through the illness and also dismissed "the misconception that I was out partying".
"At times I was incapable of getting enough oxygen to get my lines out on stage and sometimes I'd forget where I was in the play."
The grievance hearing panel said in a statement that "the producers have the right, as a next step, to proceed to arbitration".
Piven's spokesman Samantha Mast said in a statement: "Mr Piven is hopeful that the producers will ultimately recognise that he did the right thing by listening to the instructions from his doctors."
She said the doctors had told Piven "to stop the play immediately and undergo enforced rest rather than continuing to perform and risk dire health consequences".
Speed-the-Plow opened in October and closed last week with Piven's role of movie mogul being taken over by other actors.
Piven, 43, who played Ari Gold in Entourage, became the target of jokes after leaving the play.
Speed-the-Plow writer David Mamet even joked: "My understanding is that Jeremy is leaving showbusiness to pursue a career as a thermometer."