Leading sources in the two main political blocs - the Shia United Iraqi Alliance and the powerful Kurdish coalition - said that Saadoun al-Dulaimi, a Sunni Arab, would be the new defence minister.
Walid Khalid, an Iraqi journalist, told Aljazeera that al-Dulaimi is a former Iraqi army officer with a reputation for his honesty.
Al-Dulaimi is thought to be the only figure able to create an atmosphere of respect in the country, Khalid said.
Ibrahim Bahr al-Uloum, a Shia, will be oil minister, sources from the National Dialogue Council and national Sunni forces told Khalid.
A formal announcement was expected later on Saturday or early on Sunday, the sources said.
Iraq's Sunni Arab minority, dominant during the rule of Saddam Hussein, was sidelined after the 30 January elections, as most Sunni Arabs had stayed away from the polls because of calls for a boycott and fears of insurgent attacks.
Shia and Kurdish leaders, trying to undermine the uprising, promised to give key cabinet posts to Sunni Arabs, including the Defence Ministry.
But disagreements over which Sunni Arabs would take the defence portfolio delayed a deal.
Several candidates were rejected by the Shia, who alleged they had been too close to Saddam's government.
There was also a dispute between the Shia and the Kurds over who would control the key Oil Ministry.
A partial cabinet was sworn in on Tuesday, with temporary ministers announced for the vacant posts.