A British soldier looks at plaques on the memorial wall in front of 20th Armoured Brigade headquarters on the main coalition military base at Basra, where a service was held on Thursday to honour the 179 British service personnel killed during the six-year conflict in Iraq. (Lewis Whyld/PA/Associated Press)The British military formally ended combat operations in Iraq on Thursday after six years of conflict by handing over control of its main base in Basra to an American brigade.

Troops stood at attention at the base as the colours of the British army's 20th Armoured Brigade were lowered at a formal ceremony to mark the end of the combat mission.

British Prime Minister Gordon Brown said the day marks the "closing chapter" for Britain's mission in Iraq.

"Today Iraq is a success story," Brown said after meeting with Iraqi Prime Minister Nouri al-Maliki in London. "Britain can be proud of our legacy that we leave there."

He also paid tribute to the soldiers who gave their lives during the mission.

"They will always be remembered for the service they have given. Our country owes them a huge debt of gratitude," Brown said.

Earlier in the day, British Defence Minister John Hutton joined soldiers in Basra for a ceremony to honour the 179 British military personnel who died during the war.

Also read during the ceremony were the names of soldiers from other countries — the United States, Italy, Denmark, the Netherlands and Romania — who were killed in Operation Telec, the code name for Britain's operation in Iraq.

The British military began handing over military command in Basra to U.S. forces last month. The pullout of most British combat troops is scheduled to be completed by May.

Following years of sectarian violence following the U.S.-led invasion of 2003, British forces in the southern oil port were forced to withdraw from the city in 2007 to the main base at the city's airport, while a 60,000 Shia militia known as the Mahdi Army seized control.

The Mahdi Army, run by radical Shia cleric Muqtada al-Sadr, was removed from Basra in a U.S.-backed Iraqi military operation ordered by al-Maliki a year ago.

With files from The Associated Press