Fatah has re-elected Palestinian president Mahmud Abbas as head of the movement.
Abbas, who took over as party chief after the death of Yasser Arafat, in 2004, was confirmed in the position by a unanimous vote on Saturday, the fifth day of its first congress in 20 years.
But a vote on the governing groups in the movement was delayed again and re-scheduled to take place on Sunday.
The congress started on Tuesday and was due to last three days. However, it has been extended after bitter arguments over reforms.
Fatah controls the Palestinian Authority. It was defeated by Hamas in a parliamentary election in 2006. Hamas now controls Gaza and Fatah is confined to the West Bank.
Fatah was founded by Arafat in the late 1950s.