After years of toiling without a pay raise, the recent salary boost is “too little, too late” for Justice Ariel Belen of the Appellate Division, Second Department.

Belen yesterday confirmed that he has accepted a too-good-to-turn-down offer from JAMS, a private alternative dispute resolution company, and will leave the bench in mid-October.

“It is a very difficult and heart-wrenching decision for me,” he said.

Although Belen (See Profile) and all the judges received 17 percent raises in April and can look forward to another hike in 2013 and 2014, he said the raise isn’t enough to make up the ground lost in the dozen years that judicial salaries were stagnant. He declined to reveal his JAMS salary, but suggested it is considerably more than the $168,600 he makes as an appellate judge.

“The pay raise was welcome, but it really was long overdue and I don’t think really changes substantially a judge’s life, particularly in New York City,” said Belen, who has a daughter in college and an autistic son.

Belen said he is grateful that Chief Judge Jonathan Lippman (See Profile) and former Chief Judge Judith Kaye worked so hard for so long to secure raises for the judges, and particularly gratified that a new process for regularly evaluating judicial salaries should ensure that judges will never again go 13 years without a raise. But he said it isn’t enough to offset the JAMS offer.

“There comes a point where the prospects of substantially increasing your income just outweigh everything else,” he said.

Belen, 55, a Supreme Court judge since 1995, was appointed to the Second Department in 2008. He was previously an administrative judge in Brooklyn, an associate justice of the Appellate Term in the Second and Eleventh Districts, and a commercial division judge.

A former supervising attorney with the Legal Aid Society, Belen also served as an assistant corporation counsel in New York City. Belen, who focused on international legal affairs at Cornell Law School, practiced criminal law before joining the Legal Aid Society.

In recent months Belen has been mentioned as a possible successor to Court of Appeals Judge Carmen Beauchamp Ciparick (See Profile), who faces mandatory retirement at the end of the year. Belen is highly regarded and, like Ciparick, Hispanic. Ciparick is the first Hispanic to serve on the Court of Appeals.

“I love what I do here,” Belen said, estimating that he has been involved in 3,500 appeals, roughly 75 a month, since his appointment to the Second Department. “This is, in effect, the highest court for about 12 million people. My entire career has been in public service. But this was an offer to me that I just couldn’t turn down. It really comes down to a financial decision.”

Belen said he will be doing mediation and arbitration with JAMS, probably with a concentration on commercial litigation, although he said he hopes to get involved in international law.

With the departure of Belen from the busiest appellate court in the state, and possibly the nation, the Second Department could be down four of its allotment of 22 judges, with yet another justice, Anita Florio (See Profile), leaving at the end of the year.

Additionally, the Second Department has been without a permanent presiding justice since last fall, when A. Gail Prudenti (See Profile) became chief administrative judge. William Mastro (See Profile) has been the acting presiding justice.

All of the Appellate Division departments are short-staffed and except for promoting Karen Peters (See Profile), who had been an associate justice in the Third Department, to presiding justice in April, and re-designating some judges whose terms expired or reached senior status, Governor Andrew Cuomo has not yet elevated a justice to the Appellate Division in his nearly two years in office.

The First Department is down three of its 20 judges, the Third has one vacancy among 12 positions and the Fourth is short 25 percent of its judges with three of 12 posts vacant.

Matthew Wing, a spokesman for the governor, said, “We anticipate announcing appointments by September.”

Belen said he feels “bad” that because of the vacancies his colleagues are carrying heavier caseloads.

“It has been extremely difficult because the work that would have been spread among those three additional judges now has to be taken up by the other judges,” Belen said. “Judge Mastro has done a wonderful job as the acting P.J., but I think he would be the first to tell you that an institution like this needs a full staff.”

Mastro confirmed that all the other Second Department judges are carrying an extra workload, and that burden will only increase when Belen leaves.

“It means that the other judges are going to have to pick up more of a caseload, but they have been doing that for a while and there haven’t been any complaints,” Mastro said. “They are professionals and understand how important this job is and rise to the occasion.”

Mastro said he was “shocked and upset” to learn that Belen is leaving.

“He is a great colleague and collegiality is something we pride ourselves on in the Second Department,” Mastro said. “He is someone who listens and commands the respect of all the other judges because he is a man of great integrity. I know how much he loved the job, how much he engaged the other judges and how he looked forward to being here and making a difference, and he did make a difference.”

Justice John Leventhal (See Profile) described Belen as “the conscience of the court, a terrific human being, a caring judge, and a very good friend on a personal level.”

Leventhal added, “I know he loved the work and he loved the give and take of oral argument and the collegiality of the bench. One thing about the Second Department, and Ariel is emblematic, is we disagree without being disagreeable. We genuinely like one another.”