Qatari-led mediators tried on Monday, the fourth day of tense negotiations in Doha, to nudge rival Lebanese leaders towards agreement on proposals aimed at ending their political crisis.

The Qatari prime minister made detailed proposals to the two sides on Sunday night and held talks with the rival leaders in the early hours of Monday, delegates said.

The Arab League intervened last week to end Lebanon's worst domestic fighting since the 1975-90 civil war and invited the country's feuding U.S.-backed government and Hezbollah-led opposition To talks in Qatar.

Iranian-backed Hezbollah fighters briefly took control of the Muslim parts of Beirut in the fighting against outgunned government loyalists that killed at least 81 people.

The Shi'ite Hezbollah fighters' routing of Sunni and Druze pro-government gunmen gave the violence a sectarian tone and threatened to plunge the country into a new civil war.

After two days of tough bargaining in Doha, Qatari Prime Minister Sheikh Hamad bin Jassim bin Jabr al-Thani presented the rivals with proposals to resolve the issues at the heart of the political conflict that had paralysed Lebanon for 18 months and left it without a president since November.

Sheikh Hamad made the proposals verbally on Sunday night and held separate talks with the rivals into the early hours of Monday, delegates said.

He expected answers from both camps later in the day. He had made specific proposals on the two main issues: the formation of a new government and a new election law.

Agreement would pave the way for parliament to elect army commander General Michel Suleiman as president.

The main sticking point appeared to be over the formation of the government, the delegates said. Sheikh Hamad proposed a cabinet of 30 ministers in which the ruling coalition would have 13 seats, the opposition 10 and the new president would name the remaining seven ministers.

OPPOSITION DEMANDS VETO

Opposition delegates said they would not agree to a proposal that did not guarantee the opposition veto power in cabinet - or 11 ministers. They said a suggestion that the opposition would have a main say in naming one of the president's ministers would not be enough.

The proposals include referring to parliament for review and approval a law for the 2009 general election that was drafted by a government-appointed committee of legal and constitutional experts.

The Qatari proposals were made after the emir, Sheikh Hamad bin Khalifa al-Thani, added his weight to the talks, meeting the leaders to try to bridge differences.

He brought together Prime Minister Fouad Siniora and Parliament Speaker Nabih Berri, a senior opposition leader, for the first time in 18 months.

Delegates did not say whether Sheikh Hamad had made any specific suggestion over a coalition demand for clear guarantees that Hezbollah, which is backed by Iran and Syria, would not turn its guns on Lebanese again and that the fate of its arms would be debated in Lebanon soon.

Washington blames Syria and Iran for Hezbollah's offensive last week which forced the U.S-supported government to rescind two decisions that had triggered the escalation.

U.S. National Security Adviser Stephen Hadley said the Doha talks should aim to curb Hezbollah and bolster the government.

"This can lead to an end to the political stalemate, but only if it does not reward Hezbollah, and if it supports the elected government..." he said, adding that the talks were an opportunity to hold Hezbollah to account and "clip its wings."