A member of her Iraqi Islamic Party said Taiseer Najah al- Mashhadani was freed after her captors made contact with Tariq al-Hashemi, the Sunni Arab vice-president.
Her release came as Nuri al-Maliki, the prime minister, urged hundreds of tribal leaders gathered in Baghdad to unite to end the bitter sectarian bloodshed between Sunnis and Shia that has raised fears of civil war. Al-Maliki was speaking during a conference for national reconciliation sponsored by the government.
State television said after her release she met al-Maliki, who is struggling to keep his promises of easing sectarian tensions under his national reconciliation drive.
Al-Mashhadani's abduction prompted the Iraqi Accordance Front, the biggest Sunni bloc, to boycott parliament briefly. Her party is the biggest in the Front.
Gunmen seized her and seven guards in a mainly Shia district of Baghdad on July 1. Some Sunni leaders blamed the kidnapping on Shia militias, which they also accuse of death squad killings, a charge the militias deny.
Al-Mashhadani was snatched on
July 1 with her seven bodyguards
Al-Mashhdani's release and the relative success achieved as tribal chiefs vowed to work together for peace in Iraq were seen as a double victory for al-Maliki.
Much of the shine was taken off the government's successes, however, when a powerful Iran-backed politician, Abdel Aziz al-Hakim, reopened a tense debate by calling for the oil-rich Shia south of the country to be granted autonomy.
Al-Hakim, head of the Supreme Council for the Islamic Revolution in Iraq, said a referendum should be held in the region to endorse a breakaway, an idea which is fiercely opposed by Sunni and nationalist leaders.
Al-Hakim's office in Najaf issued a statement on Saturday that said: "Our biggest assurance to our people is that federalism be implemented in the centre and south of Iraq."
He was quoted as saying: "This is a guarantee to our sons and grandsons that injustice will not be revived."
He was referring to the period under Iraq's former ruler, Saddam Hussein, who the Shia claim oppressed them.
Iraq has been plunged into chaos
since the 2003 US-led invasion
Federalism has strong support among al-Maliki's own Shia group and the Kurdish minority in the north.
Sunnis fear, however, that an autonomous Shia region would seize the lion's share of Iraq's oil wealth and fall under the influence of neighouring Iran, which allegedly arms militias linked to Shia political parties.
Abdulrazak Suleiman, a Sunni tribal leader, called for federalism to be put on hold for five years and implicitly accused Shia militias of receiving Tehran's support.
He told delegates at Saturday's reconciliation meeting: "We demand a professional Iraqi army. We should dismantle militias and prevent neighbouring countries from interfering in Iraqi affairs."
Iraq has been plunged into chaos since 2003, when Saddam was overthrown in a US-led invasion, creating a power vacuum which has been exploited by religious militias and death squads.