* Two weeks of protests close major highway to Jordan, Syria
* Syrian crisis fueling worries over Iraq's sectarian mix
* Power-sharing government deadlocked since U.S. troops left
By Raheem Salman
BAGHDAD, Jan 9 (Reuters) - Iraq closed a border crossing with Jordan on Wednesday after Sunni Muslim demonstrators blocked a highway to Syria and Jordan as part of mass protests against Shi'ite Prime Minister Nuri al-Maliki.
Baghdad ordered troops to shut the Traibil border post in the Sunni heartland province of Anbar, where protests erupted in late December after authorities arrested the bodyguards of a Sunni finance minister, local officials said.
The unrest is unfolding into a major test for Maliki, a Shi'ite nationalist whom many Sunni leaders accuse of marginalising their sect and amassing power, just a year after the last American troops withdraw from the OPEC oil producer.
Sunni protests are fuelling Iraqi worries about Syria, where the battle between mostly Sunni insurgents against President Bashar al-Assad, an ally of Shi'ite Iran, is stirring regional sectarian tensions and testing Iraq's own fragile balance.
Several thousand demonstrators are camped out on the highway near the Sunni stronghold of Ramadi, about 100 km (60 miles) west of Baghdad, before the point at which it splits, with one road leading to Syria and another to Jordan.
Troops closed the Traibil crossing, Iraq's only major frontier point with Jordan, early on Wednesday until further notice. Authorities cited disruptions to transport and trade.
"Our work has halted completely," Colonel Mahmoud Mohammed Ali, deputy chief of border police at the crossing told Reuters by telephone. "There are no trucks, no passenger cars, and officials at the gate are not working."
Protests broke out in December after Finance Minister Rafaie al-Esawi's bodyguards and staff were detained on terrorism charges. Sunni leaders saw the arrests as part of a sustained crackdown on their sect by Iraq's Shi'ite leadership.
Sectarian tensions remain raw in Iraq, which endured years of Sunni-Shi'ite bloodshed shortly after the U.S.-led invasion that toppled former strongman Saddam Hussein in 2003.
Many Sunnis say they feel sidelined since elections in a post-Saddam Iraq empowered majority Shi'ites, although Shi'ite leaders point to Sunnis in important posts such as speaker of parliament as evidence that power-sharing is genuine.
CRISIS AFTER CRISIS
Violence in Iraq has eased, but the government made up of Shi'ite, Sunni and ethnic Kurdish blocs has been deadlocked over how to share power since American troops left in December 2011.
Complicating the attempts to ease Sunni protests, the Arab-led central government in Baghdad is also caught in a standoff over oil with Iraq's autonomous Kurdistan enclave, where ethnic Kurds run their own regional government.
The arrest of Esawi's men came a day after President Jalal Talabani, a veteran Kurdish statesman who has long mediated among Iraqi, went abroad for medical treatment after a stroke.
Maliki, who spent years in underground exile fighting Saddam and later helped purge members of the Sunni ruler's outlawed Baathist party, has made small concessions to the Sunni protesters, but these have failed to end the unrest.
"It is in the interest of the government for people go out and demonstrate to express their rights," he said on Wednesday. "But some want confrontation between police and demonstrators to say there is no liberty or democracy."
Sunni leaders and tribal sheikhs' demands range from Maliki's removal to release of detainees and the suspension of an anti-terrorism law that Sunnis believe has been abused by authorities to target their sect unfairly.
Local Anbar officials accused the central government of trying to choke the local economy in an attempt to put pressure on protesters by closing the Jordan crossing.
"This targets Anbar's population," Sadoon al-Shaalan, deputy chief of Anbar provincial council. "This step will impact the economy of the province in general. It targets the livelihood of the people."
A year ago, another crisis erupted after authorities sought the arrest of Sunni Vice-President Tareq al-Hashemi, accused by officials of running death squads. He fled the country and was later sentenced to death in absentia.