Syria's main political opposition will attempt to nominate a new leader to unify a fractured coalition when members reconvene in Istanbul on Thursday, an official said.
Frontrunners include the secretary general of the Syrian National Coalition Mustafa al-Sabbagh, and Ahmad Assi Jarba, representing the faction of veteran secular dissident Michel Kilo.
Recognised by dozens of states and organisations as the legitimate representative of the Syrian people, the umbrella group is seeking a successor to interim president Georges Sabra, who may also seek nomination.
The opposition has been rudderless after the departure in May of Ahmad Moaz al-Khatib in protest at the world's "inaction" over Syria's civil war.
Coalition member Samir Nashar told AFP: "The names of Ahmad Assi Jarba, representing Michel Kilo's faction, and Mustafa al-Sabbagh, representing the local councils, are being formally proposed as possible leaders for the coalition, but there could be surprises.
"Informally, the names of Burhan Ghalioun, Georges Sabra and Louay Safi are also being discussed. But of course we never know.
"If there is speedy agreement on the name of the new president, then I would still have some hope," Nashar said Wednesday.
"Of course the coalition's last meeting was very difficult, and if things get blocked, then I think there will be some serious consequences that will affect both the coalition and the way it is perceived, both by its friends and its enemies."
The nomination of a new chief had initially been mooted for the end of May but was postponed after eight days of talks stalled in the face of conflicting views on the future direction of the coalition.
Under pressure from Saudi Arabia, Qatar and other regional powers, the opposition agreed in the May meeting to accept new groups under the umbrella of the coalition, lessening the influence of a strong Muslim Brotherhood faction backed by Doha.
The nomination of vice-presidents and other senior leaders was also on the agenda at the opposition group's general assembly, to be held over two days in the Turkish city.
The coalition will also likely discuss a future peace conference dubbed "Geneva 2" they have deliberated over attending, named after a meeting in the Swiss city a year ago that set up the transitional government but did not agree on the fate of Syria's President Bashar al-Assad.
US Secretary of State John Kerry said Tuesday that the United States and Russia were committed to holding a peace conference on Syria but that it would likely take place after August.
A Western diplomat told AFP: "We hope the coalition will present a united front this time after the difficulties we saw in May. It is key given that events are not turning in their favour".
The assembly takes place after a series of setbacks for the rebels including the fall of Qusayr to Assad's forces, a former rebel bastion near the Lebanese border, aided by fighters from Lebanon's Shiite Hezbollah movement.
Regime troops' current targets are Homs, in central Syria, and rebel bastions near the capital Damascus. UN leader Ban Ki-moon on Tuesday expressed fear for 2,500 "trapped" civilians in Homs city.