"We want to end the shared role of Lebanese and Syrian intelligence in all Lebanese life," Walid Jumblatt, Lebanon's Druze political leader, said.
A statement from the meeting called on Syria to end its hegemony in Lebanon and "and restore sovereignty to the Lebanese" - a demand that has grown louder ahead of parliamentary elections expected in May.
Politicians who curry favour with Damascus usually win a majority of seats in the 128-member assembly.
Possible poll rigging, gerrymandering and the Syrian-backed government's manoeuvres against the opposition were among factors that threatened the vote's integrity, the statement said.
Syria must withdraw in order to "end the dangerous crisis between Lebanese authorities and international legitimacy that occurred after (Security Council) Resolution 1559 was issued", the statement said.
Syria has made minor redeployments in recent years but pressure is growing for it to relinquish its grip on Lebanon completely. US and French officials routinely demand a Syrian pullout and an end to interference in Lebanese affairs.
UN envoy Terje Roed-Larsen, appointed to follow up on the resolution, plans to visit Beirut early next week, after stopping off in Syria, to discuss implementation of the resolution, UN officials said.