Judge Rosemary Barkett will step down in September from the U.S. Court of Appeals for the Eleventh Circuit after 20 years to join the Iran-U.S. Claims Tribunal at The Hague in the Netherlands.

The international arbitral tribunal has three U.S. judges, three from Iran and three from neutral countries.

The judge could not be reached for comment by deadline. A clerk at the Eleventh Circuit said late Monday that any questions for the judge would have to be submitted in writing.

The move by Barkett, a former Florida Supreme Court justice, would leave an opening for a judge from Florida on the Atlanta-based appellate court assigned to hear cases from Florida, Georgia and Alabama. The last Florida opening was filled by Adalberto Jordan, who was a U.S. district judge in Miami.

The Iran-U.S. Claims Tribunal was established in 1981 by the two countries to resolve claims by people as well as nations. Several large and complex claims between the two countries are currently on the docket.

"It's a great recognition for her and her achievements and for her to contribute to public service in a slightly different way," said attorney John Barkett, the judge's nephew and a partner at Shook, Hardy & Bacon in Miami.

Rosemary Barkett was appointed a state circuit judge in 1979 by Governor Bob Graham. She served on the Fourth District Court of Appeal in 1984 and 1985 before she became the first woman on the state's high court and its first female chief justice.

She was nominated to the federal appellate court by President Bill Clinton in 1993.

Barkett, a former nun, talked about her interest in international law last year at an event sponsored by the Federal Bar Association's South Florida chapter. She chaired an initiative for a subcommittee of the American Bar Association for North Africa and the Middle East.

Her duties included visiting the region and meeting with legal and political leaders. Barkett has given numerous speeches to aspiring Middle Eastern law students and those interested in reform.

John Barkett noted his aunt has been on the bench for 34 years and has heard more than her share of death penalty cases. He said the opportunity was too good to pass up.

"This is just a wonderful opportunity," he said. "She loves the Eleventh Circuit. She loves the judges on the court."