CAIRO - The two main rival Palestinian factions began a new round of talks in Cairo on Sunday, the official MENA news agency reported, facing a 10-day deadline for a reconciliation agreement.

"The two delegations, who had a working dinner on Saturday evening, met (on Sunday) for a sixth round of talks," MENA reported.

Cairo has been mediating talks between president Mahmud Abbas's Fatah party and the Islamist Hamas movement aimed at healing bitter divisions between the two since Hamas seized control of the Gaza Strip in 2007.

The factions will also meet intelligence chief Omar Suleiman ahead of a July 7 target date to sign an agreement which will lay out an electoral law, define the make-up of security forces and of a committee that will liaise between the Gaza Strip and the West Bank ahead of an election in 2010.

But Hamas expressed pessimism on the eve of the talks.

The Islamist movement has demanded that Abbas's Palestinian Authority release all "political prisoners" -- referring to the scores of Hamas members arrested in the Israeli-occupied West Bank -- or provide a timetable for their release.

Both Fatah and Hamas have accused each other of persecuting their rivals in the territories under their control, and both groups have been accused by human rights groups of arbitrary arrests and mistreatment of detainees.

"Any hope of reaching an agreement on July 7 basically depends on how Fatah deals with the issue of political prisoners," Omar Abdelraziq, a senior Hamas official in the West Bank, told AFP on Saturday.