* Bickering for years, both sides now seek benefits of unity
* Reconciliation push coincides with peace talks drive
* Few Palestinians see end of duel near (adds arrival to Gaza, quotes, background)
By Nidal al-Mughrabi
GAZA, April 22 (Reuters) - Palestine Liberation Organization delegates arrived in Gaza on Tuesday to discuss unity with militant group Hamas for the first time since their 2007 conflict, in a potential boost for Palestinian president Mahmoud Abbas.
Few Palestinians expect a breakthrough in the deadlock that has paralysed Palestinian politics, and many have low expectations of any resolution to the seemingly endless duel.
A deal could restore a measure of sovereignty to Abbas in Gaza and boost his negotiating power with Israel in any future peace talks, although such a partnership could also provoke a backlash from Israel against the PLO in the occupied West Bank.
The reconciliation mission coincided with a meeting between Abbas's Fatah-led group and Israeli peace negotiators in Jerusalem to try to extend talks beyond an April 29 deadline.
Hamas and Fatah have failed since 2011 to implement an Egyptian-brokered unity deal because of disputes over power-sharing and the handling of conflict with Israel.
Azzam Al-Ahmed, a senior Fatah official, denied that the attempt to negotiate a deal with Hamas was designed merely to strengthen Abbas's hand in talks with Israel.
"We want to end the division whether there is negotiation (with Israel) or there isn't. We want to build Gaza and the West Bank and end the (Israeli) occupation," Al-Ahmed told official Palestinian news agency WAFA.
"We are one country, one people and no power on earth could dismantle this holy bond ... We must end the ugly chapter of division and implement everything we have signed," Al-Ahmed said on arrival in Gaza.
Arab-brokered unity pacts reached between the two sides have yet to be implemented after years of mutual blame.
"NO ROOM FOR FAILURE"
But if Palestinian unity talks end with a deal, paving the way for elections and a national strategy towards Israel, not only might Abbas gain negotiating power, but Hamas, hemmed in by an Israeli-Egyptian blockade, might become less isolated.
"We must conclude national reconciliation and end the division so we can have one government, one political national agenda and one system ... There is no room for failure at this dialogue," Hamas prime minister Ismail Haniyeh said.
The two sides disagree on policy toward Israel. Islamist Hamas refuses to renounce using force against the Jewish state while secular, Western-backed Fatah wants a deal with Israel to set up a Palestinian state in Gaza, the occupied West Bank and East Jerusalem - lands Israel captured in 1967.
Hamas and Fatah also trade blame over the dozens of prisoners held by each side since Hamas took control of Gaza and Fatah remained the predominant party in the Israeli-occupied West Bank after Hamas won 2006 parliamentary polls.
"Palestinians in Gaza and the West Bank believe more in what they see, not in what they hear," Gaza political analyst Hani Habib told Reuters. "Past experiences have taught them that, every time, something happens at the last moment and makes their hope evaporate." (Editing by Louise Ireland/Ruth Pitchford)