Political observers say the outcome of this crucial round of voting may well determine the future shape of the Christian leadership, with parties opposed to the erstwhile Syrian presence in Lebanon needing 45 seats to win a majority in parliament, according to Aljazeera.
Anti-Syrian Christian leader Michel Aoun is heading for victory against rival Christian politicians, and Aljazeera reports that Druze leader Walid Jumblatt has acknowledged Aoun as the winner.
The defeat of several prominent Christian figures opposed to Syria's role in Lebanon will be sure to complicate the next 128-seat parliament's task of charting the country's new political course.
The elections, held over four weekends ending 19 June, are set to usher in a parliament with most legislators opposed to Syria for the first time since the 1975-1990 civil war.
Unofficial partial counts on Sunday showed candidates backed by Aoun set to clinch 15 out of 16 seats up for grabs in the third round of the elections in the Maronite Christian heartland of North Metn and Byblos-Kesrwan north of Beirut.
But the candidates of former army chief Aoun, who fell out with other anti-Syrian leaders after returning in May from 14 years in exile, looked set to be beaten by a list backed by Jumblatt in the Baabda-Aley district, where 11 seats are being contested.
Jumblatt's list won all eight seats in the mainly Druze Shouf constituency.
Hizb Allah victories
The Shia Islamic Hizb Allah also looked set to increase its share in parliament ,with six members winning seats in the eastern Baalbek-Hermel district. The group has already won seven seats in the first two rounds of the election.
Syrian troops withdrew from Lebanon in April after popular protests and pressure from the US, France and other powers, which are likely to urge any new government to disarm Hizb Allah and implement political and economic reform.
"I am staying until the last moment in my tenure and this is because I believe that the constitution says so"
More than half of the 1.25 million eligible voters cast ballots in the Mount Lebanon and eastern Bekaa Valley regions in the penultimate stage of Lebanon's first national election without the presence of Syrian troops for three decades.
The Interior Ministry said turnout was 54% in Mount Lebanon and 52% in the Bekaa.
But international concern over accusations of Syrian intelligence activity in Lebanon cast a shadow over the poll.
The US says it has information about a Syrian hit list of Lebanese leaders, a charge Syria denies.
UN chief Kofi Annan decided last week to send a verification team back to Lebanon to check charges that Syrian intelligence agents were still in the country. An envoy, Terje Roed-Larsen, met Syrian President Bashar al-Assad on Sunday.
A UN spokesman said Roed-Larsen headed straight back to New York to brief Annan on the talks. He gave no details.
Hassan Nasarallah's Hizb Allah is
set to increase its seat count
A total of 58 seats were up for grabs on Sunday.
Forty-two lawmakers were elected in the first two rounds in Beirut and the south, both of which brought no surprises.
The son of assassinated former prime minister Rafik al-Hariri won all seats in the mainly Sunni capital and a joint Hizb Allah and Amal list of candidates triumphed in the southern Shia heartland.
The new parliament is set to decide the fate of pro-Syrian President Emile Lahoud, address the disarming of pro-Syrian Hizb Allah, reshape ties with Syria and draft a new election law.
Several opposition leaders - but not Aoun - want Lahoud to go, accusing him of playing a role in al-Hariri's death.
But the Lebanese president is defiant. "I am staying until the last moment in my tenure and this is because I believe that the constitution says so," Lahoud said after casting a ballot.
Old women in traditional Druze dresses were carried to polling stations while old men were helped up stairs to vote as election fever swept a swathe of picturesque mountain villages.
Druze leader Jumblatt has allied
with former Christian enemies
Many voters in the mainly Druze town of Aley, 16km east of Beirut, said they voted for a Jumblatt-backed ticket grouping Druze and Christian groups who battled each other during Lebanon's civil war.
"These alliances should happen so that we can forget the past. This is the only way to get over the war," Nada Najed, a housewife, said as she lined up outside a polling station.