Prime Minister Ismail Haniyeh of Hamas had asked the factions to submit names ahead of a planned meeting on Saturday with President Mahmoud Abbas of Fatah in the Gaza Strip.

Hamas and Fatah officials offered no immediate explanation for the delay and it was unclear how long it would last. Both sides promised to accelerate formation of a unity government, fearing opponents would try to use any delay to scuttle the deal.

"We know that both Hamas and Fatah are serious about speeding up the presentation of their chosen candidates for ministerial posts and they could do so within the next two days," said Haniyeh aide Ghazi Hamad.

Hamad said he expected Abbas and Haniyeh to meet on Sunday, rather than Saturday. "I do not expect major obstacles before the formation of the government," he said.