BEIRUT - Lebanon's pro-western government and Hezbollah, the Shiite Muslim party that leads the opposition, seek an end to 18 months of political stalemate today in talks brokered by the Arab League.

Representatives of Prime Minister Fouad Siniora and the opposition are scheduled to meet in the Persian Gulf state of Qatar to discuss electing a new president and forming a national unity government.

Talks will "continue until an accord is struck,'' Qatar Prime Minister Sheikh Hamad bin Jassim Al-Thani said yesterday.

The 22-member Arab League intervened after armed Hezbollah militants and allies besieged parts of Beirut on May 7 and closed off the city's airport in a dispute with the government that generated Lebanon's worst sectarian crisis since the 1975- 1990 civil war.

Hezbollah stormed Beirut neighborhoods after Siniora threatened to shut an airport surveillance system and dismantle a covert telephone network operated by the party. The government viewed the installations as part of a Hezbollah-run authority outside of its control. Hezbollah defended the systems as a necessary military shield against Israel. The militia fought a 33-day war with Israel in 2006.

Sectarian Violence

Violence flared in Beirut between Shiite and Sunni Muslims, who largely support the government. Members of the Druze minority, which mostly backs the government, clashed with Hezbollah militiamen in mountains to the east. In the northern port city of Tripoli, Sunnis attacked an Alawite minority that supports Hezbollah. About 80 people died.

Yesterday's agreement includes a provision that all parties remove armed supporters from the streets and stop inciting sectarian tensions.

The first flight into Beirut's airport took off from Cyprus shortly after the announcement. Witnesses said bulldozers operated by Hezbollah members cleared roads and bridges leading to the airport.

French Foreign Minister Bernard Kouchner welcomed the agreement and called on all parties to ensure the talks beginning today "will swiftly lead to a presidential election, the formation of a national unity government and the drafting of a new electoral law.''

Hezbollah has threatened to bring down the government since November 2006, when it quit the Cabinet because Siniora refused to grant it and allies veto power.

Military Activity

By trying to ban Hezbollah's phone and surveillance systems, the government effectively tried to curb its autonomous military activity. On May 7, Hezbollah leader Hassan Nasrallah called the action a "declaration of war.'' The government revoked the bans two days ago.

The agreement brokered by the Arab League delegation includes the proposed election of Michel Suleiman, the army commander-in-chief, as president. Lebanon has been without a head of state since Nov. 23, when Syrian-backed incumbent Emile Lahoud left office at the end of his term. Lawmakers have failed to elect a new president on 19 occasions since.

The U.S. regards Hezbollah as a terrorist organization and has repeatedly demanded it be stripped of its arms. President George W. Bush blamed the recent violence on Iran, which along with Syria is a main supporter of Hezbollah.

"Hezbollah continues to pose a challenge to the future of the Lebanese people in terms of realizing a broad-based, deep democracy that benefits all of the Lebanese people,'' State Department spokesman Sean McCormack said yesterday.

The U.S. won't "second-guess anything that the Lebanese government has done in this matter with Hezbollah,'' McCormack said, when asked whether the agreement was a sign Siniora had backed down to the group.