GAZA — The Palestinian militant group Hamas announced Saturday that its political leader, Khaled Meshal, would not seek re-election, opening the door to a possible leadership contest and adding to the uncertainty enveloping Hamas at a time of regional turmoil.

Mr. Meshal, who has led the group’s political bureau since 1996 and is the face of Hamas’s leadership, told the Shura Council, the group’s highest decision-making authority, that he preferred not to run in elections scheduled in the coming months, Hamas said in a written statement. There was no immediate comment from Mr. Meshal, who is based in Damascus, the Syrian capital.

The announcement has set off abundant speculation about the future of a group already in flux.

But Mr. Meshal’s decision may also not be final: his colleagues in Hamas, while respecting his decision, urged him to reconsider and to leave the issue up to the Shura Council, according to the statement. Fawzi Barhoum, a Hamas spokesman in Gaza, said that Mr. Meshal’s wishes were not binding on the council, which elects the politburo members regardless of their personal positions. Mr. Barhoum said it was very possible that the council might elect Mr. Meshal for another term.

Hamas has been buoyed by the recent rise of Islamic parties in Egypt and elsewhere in the Middle East after the Arab Spring revolts last year. But the group’s leaders in Damascus have found themselves in an increasingly uncomfortable position since the outbreak of the Syrian uprising.

Hamas has been unwilling to express support for the beleaguered Syrian government of President Bashar al-Assad, despite pressure from its Iranian backers to do so, and relatives of many of Hamas’s leaders are reported to have already left Damascus for reasons of personal safety.

An analyst close to Hamas, speaking on the condition of anonymity, suggested that Mr. Meshal, who has Jordanian residency documents, might want to quit so that he could return to Jordan because the situation in Damascus had become unbearable. Jordan has said that Hamas leaders who hold Jordanian papers can return to its territory as long as they refrain from conducting any political activities there.

Hamas is considered a terrorist organization by Israel, the United States and the European Union and is sworn to Israel’s destruction. In an interview with The New York Times in May 2009, Mr. Meshal said that Hamas should be judged on its current deeds and policies and that it was “not logical for the international community to get stuck on sentences written 20 years ago” in its charter.

Hamas won parliamentary elections in the Palestinian territories in 2006, and a year later seized control of Gaza, the Palestinian coastal enclave, after a brief factional war with its rival party, Fatah, which dominates the Palestinian Authority.

Hamas routed Fatah forces from Gaza, confining the Palestinian Authority and its president and Fatah’s chief, Mahmoud Abbas, to the West Bank and deepening the internal Palestinian schism.

Last May, Mr. Meshal and Mr. Abbas signed a reconciliation agreement brokered by Egypt that calls for genuine power-sharing. So far the agreement has not been acted upon, for the most part, though talks are under way to put it into effect.

Since signing the accord, Mr. Meshal has called for popular resistance in the form of mass protests, while not renouncing violence, a development said to have stirred internal tensions among the different branches of Hamas.

Salah al-Bardaweel, a Hamas official in Gaza, said he did not believe that the reconciliation agreement would be affected by Mr. Meshal’s decision to step aside. “Mr. Meshal did not meet Mr. Abbas in his personal capacity,” Mr. Bardaweel said, adding that “the deal was an agreement between institutions, not individuals.”

Some Hamas officials in Gaza have noted that Mr. Meshal’s decision not to run for re-election is in line with the group’s internal regulations that say the politburo chief cannot serve more than two terms in a row, though the officials did not specify the length of each term.

Mr. Meshal took over the political bureau after his predecessor, Mousa Abu Marzook, was arrested in the United States and held in jail there for two years on suspicion of terrorism, before being deported to Jordan in 1997. Mr. Marzook became Mr. Meshal’s deputy, and he is considered to be a likely candidate to replace him.

Hamas officials speak cautiously about such issues because matters related to the group’s structure and decision-making processes are considered secret. Members of the politburo, which includes Hamas leaders from inside the Palestinian territories, Israeli prisons and the Palestinian diaspora, are elected secretly. Even the date of the leadership elections has not been publicized, but one Hamas official said that they would take place in April.

In 1997, agents from the Israeli intelligence service posing as Canadian tourists tried to assassinate Mr. Meshal on a street in Amman, Jordan, by injecting him with poison, but they were captured by Jordanian authorities. King Hussein demanded that Israel hand over the antidote to save Mr. Meshal, who was in a coma. Israel did so, and its agents were released.

The prime minister of Israel, Benjamin Netanyahu, who was then serving his first term, was also forced to release Sheik Ahmed Yassin, the founder and spiritual mentor of Hamas, and 19 others from prison in Israel.