Senior Hamas officials say the group's leader-in-exile, Khaled Meshaal, has decided to step down, clearing the way for the movement to choose a new head for the first time in nearly 16 years.
Meshaal aide Izzat Risheq said Monday that Meshaal told a Hamas leadership meeting in Cairo last week that he will not run in upcoming elections for the top position. Moussa Abu Marzouk, Meshaal's deputy, also confirmed the decision.
Meshaal and other Hamas officials have made no public comment on his future leadership or on the Cairo meeting.
Earlier this year, Meshaal angered Hamas' Gaza-based leadership by agreeing that its main rival, the Fatah movement of Western-backed Palestinian President Mahmoud Abbas, could lead any future unity government.
Egypt has brokered a reconciliation pact between Hamas and Fatah, which fought a brief civil war in 2007 that left the Islamist group in control of the Gaza Strip and Abbas in charge of the West Bank. But the two factions have not been able to reconcile and the pact has not been implemented.
Meshaal also has voiced what critics in Hamas saw as approval for Abbas's now-stalled talks with Israel, saying in 2011 that 20 years after a 1991 international Middle East conference, Palestinians were willing to give peace another chance.
A diplomatic source in the region said that Meshaal has "grown impatient with some of his Gaza officials" who have attempted to undermine his decisions in recent months.
Meshaal will remain in his post until a new leader is chosen, most likely by the end of the year.
The exiled chief has led Hamas since 1996. Under his leadership, the group carried out numerous suicide bombings and other attacks that killed hundreds of Israelis during a Palestinian uprising a decade ago. He also survived an Israeli assassination attack in 1997. Hamas has been branded a terrorist organization by Israel, the U.S. and the EU.
Forging an alliance with Iran and Syria, where the group has maintained its headquarters, it also has become an important regional political player. The group swept Palestinian legislative elections in 2006.
While a successor for Meshaal has not been named, the two leading candidates are Abu Marzouk, who led Hamas in the 1990s until he was imprisoned in the U.S. for two years, and Gaza Prime Minister Ismail Haniyeh.
Both men support closer relations with Arab countries and Europe, while adhering to Hamas's policy of refusing Western demands to recognize Israel's right to exist.