The PLO Central Council was on Wednesday expected to endorse a decision by the Palestinian leadership to seek full membership in the United Nations in September.
Palestinian president Mahmud Abbas was to address council members at the meeting in the West Bank city of Ramallah, which got under way late morning, officials said.
In his speech, Abbas was expected to lay out details of the mechanism by which the Palestinians will approach the world body, which it is hoping to join as a full member.
The Central Council is the PLO's most important decision-making body in absence of the Palestinian National Council, the parliament-in-exile which rarely meets.
The Ramallah session comes five days after Abbas convened a gathering of Palestinian diplomats in Istanbul in a bid to finalise their strategy of seeking support for statehood when the UN General Assembly meets in September.
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Officials say they are not planning on unilaterally proclaiming a state as they did in Algiers in 1988, nor will they seek recognition from the UN as a whole.
Instead, they will continue to work for endorsement on a state-by-state basis, while applying for membership in the global body.
Approaching the Security Council would be the only way for the Palestinians to gain full membership in the UN, although backing in the General Assembly would enable them to upgrade their current status from an observer body to a non-member state.
Such an upgrade would allow the Palestinians to join all the UN agencies, such as the World Health Organisation (WHO), the child welfare agency UNICEF and the world heritage body, UNESCO.
Direct peace talks between Israel and the Palestinians broke down last autumn, just weeks after they were launched, in an intractable spat over Jewish settlement building.
Since then, the Palestinians have adopted a diplomatic strategy centring on the approach to the UN in a step fiercely opposed by both Israel and Washington.