GAZA, Dec 5 (Reuters) - Hamas chief Khaled Meshaal will make his first visit to the Gaza Strip on Friday to attend the Palestinian Islamist group's 25th anniversary rally, Hamas sources said on Wednesday.

The two-day visit comes in the wake of last month's air offensive by Israel against Hamas and other armed Islamist factions to stop them firing rockets from the enclave at southern Israeli towns.

Gaza has become Hamas' stronghold since it evicted the rival Palestinian Fatah movement by force in 2007, with Ismail Haniyeh as its prime minister in the narrow coastal territory blockaded by Israel in coordination with southern neighbour Egypt.

Meshaal ran the group from exile in Damascus from 2004 until January this year when he quit the Syrian capital because of President Bashar al-Assad's bloody war with fellow-Sunni Muslim rebels. He now divides his time between Doha and Cairo.

It was unclear whether Meshaal's visit would mark the conclusion of a secretive Hamas internal leadership election that has been going on for the past six months.

He had declared that he wanted to leave the post, but he may bow to those among the movement's top ranks and its allies who believe he ought to remain in command.

ASSASSINATIONS

The eight-day battle between Israeli warplanes and Palestinian rockets ended on November 21 in a ceasefire, brokered by Egypt. Meshaal called it a victory over the Jewish state. Around 170 Palestinians were killed, mostly civilians, and six Israelis including two soldiers lost their lives.

Hamas sources said the visit by Meshaal, 56, was coordinated with Cairo officials.

Hamas denied seeking guarantees via Egyptian contacts with Israel that he would not be targeted for assassination in Gaza. Senior Hamas official Salah Al-Bardaweel said the group's security and armed forces would protect him.

Meshaal can expect a warm reception. Members of the movement's armed wing will guard his convoy on the 30-km (mile) route from Rafah on the Egyptian border north to Gaza City.

He has scheduled a stop at the house of the group's founder Sheikh Ahmed Yassin, whom Israel assassinated in 2004, then visit the mourning house of Ahmed al-Jaabari, the Hamas chief of staff whom Israel killed on Nov. 14, triggering the fighting.

Meshaal was expelled from Jordan in 1999, and moved to Qatar and then to Damascus in 2001. He survived a Mossad assassination attempt in Amman in 1997, when Israeli prime minister Benjamin Netanyahu was last in power.

Under Meshaal's leadership since 2004, the Islamists have refused to renounce their claim to all of pre-1948 "Palestine", but have been willing to accept a de facto Palestinian state on the lands Israel captured in the 1967 Six Day War.

Hamas rejects Israel's right to exist on the rest of the land and says it will not agree to a permanent peace treaty.

RECONCILIATION

Meshaal is expected to address Saturday's Hamas anniversary rally, when it is customary to outline strategy for the near future regarding internal politics as well as the conflict with Israel.

Meshaal strongly backed the diplomatic initiative by Palestinian Authority President Mahmoud Abbas to upgrade Palestinian status at the United Nations to "observer state", which the General Assembly endorsed last Thursday in New York.

In a recent interview with Reuters in Qatar, he said the de facto recognition of a sovereign Palestinian state won by his rival Abbas should be seen alongside Gaza's latest conflict with Israel as a single, bold strategy that could empower all Palestinians.

His comments revived long-stalled hopes in Gaza and the West Bank that the two Palestinian groups, who have been mutually hostile since 2007, could eventually heal their rifts and implement an Egyptian unity deal Abbas and Meshaal endorsed in 2011. (Reporting by Nidal Almughrabi; Editing by Douglas Hamilton)