A statement sent to Aljazeera on Sunday said the release came after their Turkish company announced it would stop its activities and completely withdraw from Iraq.
A group calling itself the Abu Bakr al-Siddiq Battalions threatened in a videotaped statement on 18 September to kill the workers within three days if their employer did not quit Iraq.
The construction firm, Vinsan, said three days later that it was suspending its operations in Iraq to save the men.
Scores of foreigners have been seized in Iraq since April 2003. At least 32 have been killed, including Turkish truck drivers.
Meanwhile clashes erupted between US forces and a group of Iraqi fighters in several neighbourhoods in the city of Hyt, west of Iraq, Aljazeera has learned.
A video tape depicting the fighters taking position in Hyt was sent to Aljazeera. The video also showed Iraqi fighters seizing a US civilian vehicle and communications equipment.
The clashes, in which rockets and automatic guns were used, destroyed two US military vehicles that were part of a military convoy.
Aljazeera also learned that fierce clashes erupted between US troops and armed men in central, southern and eastern neighbourhoods of Ramadi.
During the clashes, an explosive device detonated as a US military patrol was passing. A number of US soldiers were injured in the blast.