Jeremy Piven is not off the hook yet.

The producers of "Speed-the-Plow" said Friday they will file for arbitration to settle their dispute with the actor for abruptly quitting the Broadway show after his doctor said he was suffering from mercury poisoning.

The action came after no agreement was reached Thursday in a grievance hearing requested by the producers. A panel composed of Actors' Equity and Broadway League representatives were unable to reach a required unanimous decision.

In a terse, two-sentence statement, the producers said: "The grievance went as expected yesterday. The grievance committee (made up of League and Equity representatives) did not rule for either side and we will be filing for arbitration as provided by our contract."

No date was given for the filing by lead producer Jeffrey Richards.

Samantha Mast, Piven's spokeswoman, said: "We're not aware the producers have filed anything to initiate an arbitration, but if they do so, we are confident that the producers will not prevail in arbitration, just as they did not prevail in the grievance proceeding they initiated."

Under Actors' Equity rules, the arbitration will be heard by a professional arbitrator, acceptable to both Equity and the League. He or she will be chosen from a list of nine designated people, who will hold the hearing within 30 days of the filing and issue a decision within 30 days of that meeting.

The 43-year-old Piven, the Emmy- and Golden Globe-winning star of HBO's "Entourage," departed the production of David Mamet's satiric comedy after his physician said he had high levels of mercury in his body.

In a tearful interview with The New York Times after Thursday's hearing, Piven said his illness stemmed from eating fish twice a week for 20 years, not from consuming too much sushi, as some reports suggested.

"Speed-the-Plow" opened last October to favorable reviews and by the time the revival ended its limited engagement Feb. 22 at the Ethel Barrymore Theatre, it had recouped its $2.26 million production costs.

Three different actors _ understudy Jordan Lage, Norbert Leo Butz and William H. Macy _ followed Piven in the role of movie mogul Bobby Gould. Mamet's three-character play about Hollywood glamour, sex and power, also starred Elisabeth Moss of AMC's "Mad Men" and Raul Esparza.

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