BAGHDAD - Iraq's largest Sunni Arab political bloc returned to the government fold Saturday after calling off a nearly one-year boycott of the Shiite-dominated leadership -- a critical stride toward healing sectarian rifts.

The return of the National Accordance Front does more than politically reunite some of Iraq's main centers of power.

It was seen as a significant advance toward reconciliation and efforts to cement security cooperation between Shiite-led forces and armed Sunni groups that rose up against al-Qaida in Iraq.

The United States has pressured Iraq's government to work toward settling the sectarian feuds, which brought daily bloodshed until recent months. The hope is that more parties staked in the future of Iraq could mean a quicker exit for U.S. and other foreign forces.

Iraq's sharply improved security situation is already bringing plans for a pared-down British force.

On a visit to Baghdad, British Prime Minister Gordon Brown said plans are being made to scale back troops in Iraq, but he refused to consider an "artificial timetable" for withdrawing Britain's remaining 4,000 soldiers.

Brown's comments -- following meetings with Iraqi leaders -- come in advance of a scheduled address to British lawmakers on Iraq, when he is expected to give more details on troop reduction plans as insurgent attacks and militia violence drop sharply around Iraq.

The break in the Iraqi political impasse came after parliament unanimously backed Sunni candidates to fill the post of deputy prime minister and head five midlevel ministries, including higher education and communications. Four other Cabinet posts were filled by Shiites.

The Front pulled its members from the 39-member Cabinet in August, complaining it was sidelined in important decisions. The political rift left Prime Minister Nouri al-Maliki's government without partners in bids to find common ground with Sunni leaders.

Sunni Arabs, who represent about 20 percent of the country, were highly favored under Saddam Hussein, but the tables turned after his ouster when Iraq's majority Shiites held sway. The rivalries spilled over into a wave of sectarian killings and al-Qaida in Iraq bombings apparently aimed at triggering civil war.

But Sunni sheiks last year began to organize militias -- which came to be known as Awakening Councils -- against insurgents. Their role has been considered key in undercutting al-Qaida in Iraq and helping reduce violence to its lowest levels in four years.

Get $150+ in coupons in every Sunday N&O. Click here for convenient home delivery.