BEIRUT (Reuters) - The leader of Lebanon's Hezbollah movement, Sayyed Hassan Nasrallah, said on Sunday the door to electing a president was "wide open" and his members of parliament would vote for ally Michel Aoun at a parliamentary session at the end of October.

Lebanon has been without a president for more than two years, part of a political crisis that has resulted in a breakdown in many basic services and concerns about the country's stability.

Lebanon's former prime minister Saad al-Hariri said on Thursday he would back Christian leader Aoun to be president. Hariri stressed that his endorsement was a "political settlement" for the benefit of the whole country.

"The past few days saw an important development: a declaration by the Future Movement leader (Hariri) of his support for the nomination of General Michel Aoun for the presidency. The door is now realistically wide open for a successful presidential election," Nasrallah said.

Parliament will convene on Oct. 31 for a session to elect the president, the 46th such sitting since the term of the last president, Michel Suleiman, expired in 2014. Each of the previous sittings failed to gain the two-thirds quorum needed for a vote.

The position of president must be filled by a Maronite Christian.

Nasrallah spoke at a commemoration event for a Hezbollah military commander recently killed fighting in the Syrian city of Aleppo. Iran-backed Hezbollah is fighting alongside Syrian President Bashar al-Assad in the country's conflict.

(Reporting by Laila Bassam and Lisa Barrington; editing by Andrew Roche)