The PLO has confirmed 83-year-old Palestinian President Mahmoud Abbas as its unchallenged leader in a carefully staged four-day event.
The PLO parliament also backed Mr Abbas’s positions in several resolutions early on Friday, including rejecting the idea of a Palestinian state within provisional borders.
Palestinians fear such a “mini-state” will be the core of US President Donald Trump’s eventual proposal for resolving the Israeli-Palestinian conflict.
Delegates also elected new members to the main leadership body, voting out some of the remaining Abbas critics.
The PLO, founded in the 1960s, was meant to represent Palestinians everywhere, but decision-making has shifted to the Abbas-led West Bank autonomy government.
Critics say that in the absence of Palestinian general elections, the PLO serves largely to lend legitimacy to Mr Abbas’s increasingly autocratic rule in the West Bank.