The National Assembly's defence committee approved on Wednesday the Defence Ministry bill to withdraw 1000 troops from the 3200-strong South Korean contingent in Iraq in the first half of 2006.
Of the committee's 14 members, 10 voted for the bill and three opposed it, with one abstention.
The bill, which requires endorsement from the assembly's plenary session, stipulates that the reduced contingent of troops would extend their stay in Iraq for another year until December 2006.
South Korean troops have been stationed in the northern Iraqi town of Arbil for relief and rehabilitation efforts since September 2004.
The contingent is the third-largest force in the war-ravaged country after those of the United States and Britain.
In January 2004, South Korea's parliament had approved the deployment of up to 3600 troops in Iraq.
The deployment, which was renewed in November 2004 for another 12 months, needs annual parliamentary approval.
Japanese to stay
Meanwhile, Japanese officials have approved a government plan to keep non-combat troops in Iraq for up to a year beyond the 14 December expiry of their current mandate.
Japan has 550 ground troops based
in southern Iraq city of Samawa
Committees of parliamentarians from the main ruling Liberal Democratic Party (LDP) and its junior partner New Komeito agreed on the extension, which is to be made official at a special cabinet meeting on Thursday.
The plan specifies that Japan will pay close attention to the activities of international forces in Iraq, a hint at a probable withdrawal before the year ends, the Kyodo news agency said.
With their activities strictly limited by Japan's pacifist constitution, the 550 ground troops based in the southern Iraqi city of Samawa rely on British and Australian forces to maintain security in the area while they engage in reconstruction activities such as repairing schools.
Australian Defence Minister Robert Hill said last month that Australian troops providing security for Japanese engineers would probably stay in the area if Japan decided to extend its mission.
Britain has said it could start pulling its troops out in 2006.
Japanese media have said Prime Minister Junichiro Koizumi plans to bring the troops home before he steps down, at the end of his term in September next year.
Koizumi's decision to send the troops helped to cement his close ties with US President George Bush.
Koizumi's (R) move to send troops
helped cement his ties with Bush
But the mission is the most dangerous undertaken by Japanese troops since the second world war and is unpopular with Japanese voters, 77% of whom said they opposed an extension in a Mainichi Shimbun poll published in October.
Iraqi Prime Minister Ibrahim al-Jaafari, during a meeting with Koizumi in Tokyo on Monday, praised the Japanese troops' activities and urged Japan to keep them in place.