Divisions in Hamas have been brought to the surface by a reconciliation agreement with rival group Fatah, exposing splits in the Palestinian Islamist movement that could complicate implementation of the deal.

It is the first time differences between Hamas leaders in Gaza and the movement's exiled politburo in Damascus have been aired so openly in public, supporting a view that the group is far from united.

The disagreements have embarrassed a movement that has always denied talk of internal divisions. But analysts do not believe they signal an imminent fracture: neither wing of the Hamas movement can survive without the other.

Signs of strain began to show in the Hamas response to the killing of Osama bin Laden, declared a holy warrior by the head of the Hamas-run Gaza government in remarks described by a member of the exiled leadership as "a slip of the tongue". Khaled Meshaal, head of the movement in exile, then became the focus of criticism by Gaza-based leaders who said they were surprised by remarks suggesting a degree of support for peace talks between the Palestinian Authority and Israel.

Meshaal had said Hamas was willing to give "an additional chance" to the peace process always opposed by his group, which is deeply hostile to Israel and has routinely declared negotiations a waste of time.

Mahmoud Al-Zahar, a senior figure in the Gaza administration, said the comments had surprised the entire Hamas movement and contradicted its strategy based on armed conflict with Israel.

Meshaal was speaking in Cairo at a ceremony to launch the reconciliation agreement with the Fatah movement headed by President Mahmoud Abbas, head of the Palestine Liberation Organisation that opened peace talks with Israel in 1993.

MORE CRACKS POSSIBLE, BUT NO SPLIT

Zahar said Hamas had never backed negotiations nor did it support anyone else negotiating on behalf of the Palestinians.

Though decisions within Hamas are supposed to be taken through consensus, Meshaal's influence is seen as overwhelming. He is seen as the channel for the political and material backing the group receives from Syria and Iran.

Experts on Hamas believe current tensions stem from the exiled leadership's surprise decision to forge the reconciliation agreement with Fatah without proper consultation with the Gaza leadership.

The unity agreement is seen as the Palestinians' response to the popular uprisings that swept former Egyptian President Hosni Mubarak from power in February and have challenged the rule of Syrian President Bashar al-Assad, Meshaal's host since 2001.

Analysts say Hamas appeared to see reconciliation with Fatah as a way of allowing the group to build ties with Egypt's new rulers, reducing the risk of its reliance on Syria as Assad faced unprecedented mass protests.

The unity deal outlines steps to end the four-year old feud between Fatah and Hamas, whose rivalry turned into outright hostility culminating in the Islamist movement seizing control of the Gaza Strip in 2007.

The sides agreed to form a technocratic government that will reunify the administration of the West Bank and the Gaza Strip and hold elections within a year.

Political analyst Hani Habib said what appeared to be a swift decision by Hamas to sign the reconciliation agreement with Fatah was driven by "the earthquake in Syria".

In the resulting unity agreement, he said points of friction within Hamas include the fact that Moussa Abu Marzouk, Meshaal's deputy, is the group's main representative in a committee set up to agree on the new government.

Hamas may have to reconcile its own internal disputes over who should be in the new cabinet before it tables the names.

Habib said: "The reconciliation brought differences to the surface and in a deep way. We may witness more cracks but it will not lead to a division."

(Editing by Tom Perry and Philippa Fletcher)