A state appellate court has thrown a Smithtown law firm off a divorce case because it hired the judge who had originally presided over the court fight days after his retirement became public.

The Second Department of the State Appellate Division ruled that the firm could not continue to represent Devon Manditch against her husband Douglas Manditch, the chief executive of Empire National Bank.

Former State Supreme Court Justice Donald Blydenburgh became a partner in the Smithtown firm, Castrovinci & Mady, just weeks after issuing a ruling in their favor.

The court said the firm -- which became Castrovinci, Blydenburgh & Mady -- should have notified its opponent immediately when it hired Blydenburgh, a former presiding officer of the Suffolk legislature.

The decision, issued earlier this month, overruled State Supreme Court Justice James Quinn, who declined last year to throw the firm off the case.

The divorce proceeding is unresolved nearly five years after it began.

None of the attorneys involved in the case responded to requests for comment.

advertisement | advertise on newsday

In court papers, Douglas Manditch's attorney, Glenn Koopersmith of Garden City, said it "strains credulity to believe" that Devon Manditch's law firm and Blydenburgh "were not discussing, negotiating and planning for him to join the firm" while he was writing an order in favor of the firm's client.

Blydenburgh put in his retirement papers on Aug. 27, 2010, a week before he issued his final order in the case.

On Sept. 15, his retirement became public and the Castrovinci firm offered him a job on Sept. 21, while he was still on the bench, according to court papers. He began work with the firm on Oct. 1.

In his papers, Castrovinci argued that Blydenburgh had nothing to do with the Manditch case after the firm hired him, and everyone at the firm insulated him from the case.

The attempt to disqualify the firm is "calculated to financially exhaust [Devon Manditch] until she has no choice but to capitulate," Castrovinci wrote.

Blydenburgh did not respond to a call for comment.

Blydenburgh initially had ruled valid a prenuptial agreement that put the assets of Douglas Manditch, 64, off-limits to Devon Manditch, 67.

But he reversed himself in June 2010, and the final order on Sept. 3 let that reversal stand. The order is the subject of a separate appeal.