Nasser al-Ani, a senior official in the main Sunni Arab coalition, the Iraqi Accordance Front, said his political group favoured participating in broad-based coalition government, but would not begin contacts "until we get a clear picture about the results of the investigation".
"We are not taking part in discussions," he said on Thursday.
The secular Iraqi National List headed by Iyad Allawi, the secular former interim prime minister, followed the path.
"We cannot discuss issues related to the formation of a new government before a settlement is reached about the violations and complaints raised by many lists," said Mehedi al-Hafidh, a senior member of the list.
He added that members of the ticket met in Baghdad and decided to wait until final results are released and all complaints reviewed.
"We confirm that we are not part of this process of consultations to form a new government," al-Hafidh told AP.
In a related developmnent, it was announced on Thursday that a team of international assessors will review the elections following complaints that the polls were tainted by fraud.
The assessors from the International Mission for Iraqi Elections, or IMIE, will include two executive representatives from the Arab League, one executive member of the Canadian Association of Former Parliamentarians and a respected European academic, the group said in an announcement.
Preliminary results have given
Shia and Kurdish blocs a big lead
The team will travel to Iraq after an invitation from the Independent Electoral Commission of Iraq, which asked for the review after saying it had had nothing to hide.
The invitation to review the process and about 1500 complaints lodged by candidates and parties was welcomed by Zalmay Khalilzad, the US ambassador to Iraq, who said "these experts will be arriving immediately and we are ready to assist them, if needed".
The IMIE said in an announcement that the "findings of the assessors will be transmitted to the IMIE Steering Committee for review and the Steering Committee will issue a statement soon thereafter."
Preliminary results from the vote have given the governing Shia religious bloc, the United Iraqi Alliance, a big lead, but one which still would require forming a coalition with other groups.
The UN has described the elections as fair and transparent do not need to be rerun in any district. Craig Jenness, a senior UN officials, said in Baghdad on Wednesday that "complaints must be adjudicated fairly, but we in the United Nations see no justification in calls for a re-run of any election".
The Shia bloc has for the past three days been holding talks with Kurdish leaders and others politicians to begin forming a coalition government after final results are released next week.
Alliance officials have indicated the likely candidates for prime minister are Ibrahim al-Jaafari, the current prime minister who heads the Islamic Dawa party, and Adel Abdul-Mahdi, who belongs to the other main Shia party, the Supreme Council of the Islamic Revolution in Iraq.
"We confirm that we are not part of this process of consultations to form a new government"
Iraqi National List spokesman
Preliminary results, which gave a big lead to the ruling Shia religious bloc, also indicated that Ahmad Chalabi, the Iraqi deputy prime minister who is a former Washington insider, will not be re-elected to the new 275-member parliament, his office said.
In fresh violence, police and Iraqi army officials said on Thursday armed men killed 12 Shia men who were members of extended family near a town south of Baghdad.
Police Captain Hussein Shamil said the men were taken out of their homes Latifiyah, a Sunni Arab-dominated town about 30km south of Baghdad, packed them into a minivan and shot them.
"A number of gunmen broke into three houses in Latifiyah at dawn Thursday, took 12 males aged between 20 to 40 and put them into a minivan owned by one of the victims and machine-gunned them," said Iraqi Army Captain Ibrahim Abdullah.
US soldiers killed
Also on Thursday, a US soldier was killed by a bomb while on patrol in Baghdad, the military said. The military withheld the name of the Task Force Baghdad soldier pending notification of next of kin.
A bomber detonated his explosives belt on a street near the Interior Ministry office in Baghdad, killing one police officer and wounding four others, police said. Earlier police had said four were killed.
Iraqi security block a main road
leading to a bombing scene
Armed men in Baghdad assassinated an Iraqi driver working with a French company, police Captain Qassem Hussein said, adding that a university student in the al-Iskan area in northwestern Baghdad was killed in a drive-by shooting.
US air strikes launched by two F-16 fighter jets in Kirkuk province killed 10 suspects on Tuesday, the military said on Thursday.
The military said the pilots saw three men planting roadside bombs who fled when they heard the aircraft.
The pilots killed the three and seven others with them after dropping two 500lb laser-guided bombs, the military said.
Also on Thursday, hundreds of Sunni Arabs and Turkmen demonstrated in the northern oil hub of Kirkuk against the results of Iraq's general election and condemned what they called Kurdish attempts to dominate the city.
Waving Iraqi and Turkmen flags, the protesters carried banners condemning alleged electoral fraud and calling for a national unity government.
"Long live Arabs and Turkmen", said one banner, while another read "Shame on sectarians and extremists", a veiled reference to the conservative Shia list and Kurdish parties that did well in elections.
"France has no military presence in Iraq and has always called for the country to return to its full sovereignty"
French Foreign Minister
Last week has seen thousands protest election results Kirkuk, whose delicate demographic balance makes it a major flashpoint, is claimed by the Kurds as a Kurdish city, although the previous government's Arabisation policies resulted in the settlement of many Arabs in the area.
In reference to ongoing meetings between Shia and Kurdish leaders, Abdallah Mohsen al-Obedi, a Sunni Arab, said: "We are demonstrating today to show our rejection of the election results and send a message to those meeting up in the north that Turkmen and Arabs know that this is an Iraqi city."
According to preliminary figures, the Kurdish Alliance took more than half the vote in the 15 December parliamentary elections, while Sunni Arab and Turkmen lists took less than 15% each.
Last week has seen thousands of mostly Sunni Arabs protesting predicted election results around the country.
Meanwhile Philippe Douste-Blazy, the French foreign minister, called on Thursday for the immediate release of a French engineer held hostage in Iraq, emphasising that France has no military presence there.
A video shows Bernard Planche,
a Frenchman, with his captors
"Nothing justifies holding Bernard Planche in captivity," the minister said in a statement a day after the first public video of the French captive was shown on an Arab satellite channel.
Kidnappers on Wednesday released a video of Planche, who was kidnapped three weeks ago, and denounced the "illegal French presence" in the country, news channel Al-Arabiya reported.
"I again urge the captors to release our compatriot without delay," Douste-Blazy said.
"... France has no military presence in Iraq and has always called for the country to return to its full sovereignty."
Planche, an engineer working for a non-governmental organisation called AACCESS, was kidnapped 5 December on his way to work at a water plant in downtown Baghdad.
On Thursday, armed men kidnapped a Lebanese engineer in Iraq, the Lebanese Foreign Ministry said in a statement.
Camile Nassif Tannous, who works for the Schneider engineering firm, was kidnapped "in Iraq in the past few hours", the statement said, giving no further detasils.
The statement added that the Lebanese charge d'affaires in Baghdad, Hassan Hijazi, had been instructed to make "the necessary contacts" to secure Tannous' release.