CAIRO — Hamas and Fatah signed a reconciliation deal in Cairo on Thursday that aims to end their decade-old rivalry, with provisions for a joint administration that will control Gaza’s borders, including a key crossing point with Egypt, but that leaves thornier issues unresolved.

Under the agreement, which was brokered by Egyptian intelligence, Fatah will lift a series of punitive sanctions that it imposed on Hamas-controlled Gaza earlier this year.

In return, Hamas will join a new unity government scheduled to start work on Dec. 1. Palestinian officials said that, if all went well, the Palestinian Authority president, Mahmoud Abbas, could visit Gaza within the coming month — his first visit to the embattled coastal strip in a decade.

The deal was seen as a significant step to end the civil war that has split Palestinians since violent clashes between Hamas and Fatah in 2007, even if serious hurdles remain unresolved, including the status of the Hamas militant wing and its estimated 25,000 fighters.

A previous agreement between Hamas and Fatah — also signed in Cairo, in 2011 — came to nothing. Palestinian officials said the deal reached on Thursday enjoys a greater chances of success because it is backed by Saudi Arabia, the United States and, they believe, Israel.

Although he was not in Cairo, Mr. Abbas gave his blessing to the deal, which he hailed as a “final agreement.”

“I welcome the agreement reached between the Fatah and Hamas movements in Cairo,” he told Agence France-Presse, adding he gave orders to sign it immediately.

Mr. Abbas has not visited Gaza, a tiny territory that is home to 2 million people, since Hamas ejected Fatah following a series of armed clashes.

Details of the deal reached in Cairo were initially unclear. Several western news organizations were excluded from a briefing signing ceremony at the headquarters of Egypt’s General Intelligence Directorate, which brokered talks on Tuesday and Wednesday that led to the agreement.

A video supplied by a Palestinian official showed the deputy leader of Hamas, Salah al-Aruri, embraced Azzam al-Ahmad, the head of the Fatah delegation, after the signing.

Egypt’s State Information Service issued an unsigned statement saying the two rivals had “agreed on procedures” for a reconciliation government that would take effect on Dec. 1. But the statement also acknowledged continuing “division between the two sides,” and said it would host another meeting on Nov. 21.

Ahmed Youssef, an adviser to the Hamas leader, Ismail Haniya, said the two sides had agreed to joint control over the Rafah border crossing with Egypt, a key lifeline for embattled Gaza’s embattled residents.

Reacting to news reports, citing Fatah officials, that Fatah would take control of the crossing, he said: “We will discuss the possibility of allowing the presidential guard from the West Bank to control it.”

Mr. Youssef said the two sides would convene committees to integrate their ministries into a reconciliation government. One major challenge, he said, would be to reduce the bloated, 200,000-strong Palestinian civil service, which he estimated needs to be cut by as much as 20 per cent.

But, he added, the two sides had not discussed a number of key elements, including a joint strategy for dealing with Israel, the conduct of any future elections and, crucially, the state of the Hamas military wing.

Leaders from Hamas and Fatah signed a similar deal in 2011. “We have turned the black page of division forever,” said Mr. Abbas at the time, but the deal quickly foundered amid opposition from Israel which slammed it as a “victory for terrorism.”

This time, that a broad Arab coalition is backing the deal including Egypt, Saudi Arabia and the United Arab Emirates.

“This merger is going to cost a lot of money, and they will help us financially,” said Mr. Ahmed, referring to Emirati and Saudi support for the deal. “The Egyptians also clearly got a green light from America. They are obviously trying to cook up something to help end this conflict.”