Moussa Abu Marzouk told MENA that Egypt's government, which has been mediating between Hamas and Israel, would announce the truce, which will last for 18 months, in two days after consulting with other Palestinian factions.
Marzouk said a deal for the release of a captured Israeli soldier Gilad Shalit held in Gaza would be negotiated later, according to MENA.
Egypt has been trying to broker a prisoner exchange between Israel and Hamas. Hamas is holding Shalit, who was abducted more than two years ago in a cross-border raid from Gaza into southern Israel.
In Jerusalem, Prime Minister Ehud Olmert's office said the Israeli government had no comment on the report.
Earlier in the day, Egyptian and Hamas officials reported progress in truce talks, which included Hamas' strongman from Gaza, Mahmoud Zahar, and Egypt's top mediator, intelligence chief Omar Suleiman.
Hamas-Fatah reconciliation conference in works
Egyptian diplomats have been working as go-betweens to try to arrange a truce deal between Hamas and Israel to solidify a ceasefire that ended Israel's devastating 22-day offensive in Gaza last month. Hamas and Israel refuse to negotiate directly.
Marzouk told MENA that the Egyptian-brokered deal it agreed to calls for Israel to reopen six border crossings into the Gaza Strip.
Hamas leaders centered its truce demands on a reopening of the tiny coastal territory's borders, which have been largely sealed by Egypt and Israel since Hamas gunmen seized control in Gaza in 2007.
Israel, in turn, insisted that any ceasefire must include an end to militants firing rockets from Gaza into southern Israel and a halt to Hamas arms smuggling.
It was not clear what effect recent elections in Israel would have on any prospective deal over Gaza.
In talking to MENA, Marzouk did not discuss details. But earlier Thursday he told Al-Jazeera television that Egypt had previously agreed to work with Israel to forge new arrangements for reopening Gaza's crossing into Egypt.
Besides mediating a truce for Gaza, Egypt also is trying to bring Hamas and its Palestinian rival, President Mahmoud Abbas, into talks on reconciling and forming a unity government that can move ahead with peace negotiations with Israel. Egypt hopes to host a reconciliation conference Feb. 22.
Meanwhile, an Egyptian security official said Egypt had arrested a Palestinian who sneaked into Egypt through a tunnel from Gaza and was trying to purchase weapons in Egypt. The official, who spoke on condition of anonymity because he was not authorized to speak to the media, said the man and two Egyptians who were sheltering him were arrested in the coastal city of El-Arish Wednesday.