By Tom Perry and Laila Bassam

BEIRUT (Reuters) - Former Lebanese Prime Minister Saad al-Hariri intends to endorse Michel Aoun for the vacant presidency, senior political sources said, and the Hezbollah ally could be elected head of state later this month.

Long an opponent of the Iran-backed Shi'ite group Hezbollah, Hariri would become prime minister again under the plan that could reshape Lebanese politics. It has drawn opposition in his party and a final decision has not yet been taken, allies said.

The presidency, which is reserved for a Maronite Christian in the country's sectarian power-sharing arrangements, has been vacant for 2 1/2 years due to political conflicts. Aoun, a veteran politician in his 80s, has long coveted the post.

It was not immediately clear if Aoun's candidacy would enjoy enough support among other politicians to secure the necessary two-thirds quorum for the vote in the 128-seat parliament.

The next scheduled parliamentary session to elect a president is set for Oct. 31.

Opponents of Aoun's candidacy include Parliament Speaker Nabih Berri, head of the Shi'ite Amal Movement and a close ally of Hezbollah, which itself has yet to comment.

Hariri, 46, led the "March 14" alliance against Hezbollah and its allies, after the 2005 assassination of his father Rafik al-Hariri. He remains a fierce critic of Hezbollah, which is fighting in Syria in support of President Bashar al-Assad.

The proposal, unthinkable until recently, casts new light on the predicament facing Hariri, whose standing as Lebanon's most influential Sunni politician has been shaken by a financial crisis at his Saudi-based construction business.

The troubles at Saudi Oger, which has been hit by falling oil prices and cuts in Saudi state spending, have led to a cash crunch in Hariri's Future Movement.

Diplomats say Hariri has fallen from favor in Saudi Arabia, which these days cares far more about confronting Iranian influence in the Gulf and Syria than about Lebanon.


Two senior politicians told Reuters that Hariri had expressed his intention to nominate Aoun for the presidency as part of the power-sharing deal.

A third source, a member of Hariri's Future Movement, confirmed Hariri had expressed this intention, but members of his own parliamentary bloc opposed it.

Fouad Siniora, a former prime minister and head of the Future Movement's parliamentary bloc, told the newspaper Daily Star that Hariri had told his MPs on Tuesday that he had decided to support Aoun's candidacy, but added that there was "no final decision yet on this matter".

One of the senior sources said Hariri would announce his support for Aoun "within the coming few days".

The current government of Prime Minister Tammam Salam has been paralyzed by rivalries exacerbated by regional conflict.

Hariri became prime minister for the first time in 2009, but his cabinet was toppled in 2011 when Hezbollah and its allies resigned. Since then, he spent most of his time abroad.

Last year, he nominated Hezbollah ally Suleiman Franjieh for the presidency, but Hezbollah stuck by Aoun.

Aoun, a former army commander, heads the largest Christian bloc in parliament and has a large following in the divided Christian community. He has been a political ally of Hezbollah since 2006.

A significant figure in Lebanon's 1975-90 civil war, Aoun led one of two rival governments during the final years of the conflict. In 1990, the Syrian army forced him into exile.

He returned in 2005 after Syrian forces withdrew under international pressure following the Hariri assassination.

Aoun's main Christian rival, wartime enemy Samir Geagea, earlier this year also endorsed Aoun's candidacy.

(Reporting by Tom Perry and Laila Bassam Editing by Tom Heneghan)