ALEY, Lebanon – Nearly half the seats in Lebanon’s parliament will be decided Sunday in the third round of a four-stage election held as Syria continues to cast a shadow over its tiny neighbor.

Polls opened at 7 a.m. in Mount Lebanon, the mountain region surrounding Beirut and stretching north and south of the city, and in the eastern Bekaa Valley near the border with Syria.

The vote in Mount Lebanon was considered a key to the election. It is the country’s most populous region and a patchwork of religious sects and political factions that will decide Lebanon’s direction after the departure of Syria’s troops earlier this year.

Michel Aoun, a formerly staunch anti-Syrian army commander who has recently formed alliances with pro-Syrian factions, was among the first to vote Sunday. The Christian leader voted at a polling station in his hometown of Haret Hreik, where he was greeted by cheers and applause from about 200 supporters.

Wearing a T-shirt in the orange of his Free Patriotic Movement, Aoun said he hopes his group will make its debut in Parliament with at least 12 seats, and pledged a reform, anti-corruption plan. “In the end, we all bow before the people’s will,” he told reporters.

Two seats already have been won uncontested in Mount Lebanon — by Druse opposition leader Walid Jumblatt and ally Marwan Hamadeh, both lawmakers in the outgoing parliament.

In the first two rounds of voting, in Beirut and the south, seats were won almost evenly between opponents of Syria and supporters of the Shiite Hezbollah.

Anti-Syrian forces need a strong showing in Sunday’s vote — at least 45 seats for a majority — to win a firm grasp on the 128-member Parliament and wean it of Damascus’ control. But the campaign has led to some surprising alliances and left some races too close to call.

Aoun, who fought and lost a war against Syria in 1989, was one of Syria’s main Lebanese foes but recently broke with other opponents of Damascus and forged alliances with pro-Syrian politicians. Anti-Syrian opposition also teamed up with Syrian-backed Hezbollah and the pro-Syrian Shiite Amal in some districts.

Aoun says his feud with Syria is over now that Damascus has withdrawn from Lebanon. He is campaigning on a promise to fight the corruption he blames for Lebanon’s economic ills, including a national debt of over $30 billion.

Others in the anti-Syrian camp hope the elections, which end June 19 with voting in the north, will finally end Damascus’ control of the legislature.

Political tensions have spilled over into violence last week and the government sent army and police reinforcements to Mount Lebanon, the historic heart of the country. A gun battle erupted between Jumblatt’s supporters and those of his rival — and Aoun ally — Talal Arslan. At least seven people were wounded.

In the Bekaa Valley, meanwhile, Hezbollah was set to make another strong showing in the northern Baalbek-Hermel district. Elsewhere, candidates from the opposition, pro-Syrians, independents and traditional families were battling for seats.

Last Sunday, Hezbollah and its allies won 22 of 23 seats in the south. The week before, on May 29, Saad Hariri, son of the slain former premier Rafik Hariri, and his allies won 18 of 19 seats.

Syria began to remove its 15,000 troops in March, ending a heavy-handed military presence that began as a peacekeeping operation in 1976. When Lebanon’s long civil war ended, Syrian troops stayed on.

The opposition blames Syria and its Lebanese allies in government for the murders of Hariri in February and the anti-Syrian journalist Samir Kassir earlier this month.

And it was never clear whether all Syria’s separate, often shadowy intelligence forces departed as well. Syria says it removed everyone by the end of April.

Anti-Syrian Lebanese say they fear more political assassinations and have accused Syrian intelligence agents of remaining in the country in spite of international pressure and mass public protests.