By Tom Perry

BEIRUT, May 25 (Reuters) - President Michel Suleiman, the army chief elected Lebanon's head of state on Sunday, kept the military unified through three years of turmoil that pushed the country to the brink of a new civil war.

As president, his main challenge will be trying to reconcile feuding politicians who agreed that he should lead a nation paralysed by their power struggle.

"It is essential ... to work on fortifying our country and our coexistence through dialogue and to avoid transforming our country into an open arena for conflicts," Suleiman said in a speech after being elected by parliament.

Commander of the military for a decade, Suleiman kept the army out of fighting this month when the political conflict triggered Lebanon's worst civil strife since the 1975-90 war.

Instead of taking on the gunmen, his troops were deployed only to keep the peace after the battles ended in victory for Hezbollah -- Lebanon's most powerful group and an organisation with which Suleiman has enjoyed good ties in the past.

Suleiman's handling of the latest crisis was praised by Hezbollah but frowned upon by the ruling coalition for the army's perceived acquiescence in the Shi'ite group's offensive.

Despite their criticism of the army, factions in the anti-Syrian governing alliance did not withdraw their support for Suleiman as a consensus candidate for a post they had once hoped to fill with a leader from among themselves.

CHALLENGES AHEAD

Suleiman, 59, fills a chair vacated in November by Emile Lahoud -- an ally of Damascus seen by his opponents as a Syrian puppet.

Suleiman was appointed army chief in 1998, when Damascus controlled Lebanon. He coordinated closely with Syrian troops before they withdrew from Lebanon in 2005 under international pressure triggered by the assassination of former Prime Minister Rafik al-Hariri.

As president, Suleiman will have to grapple with a slew of divisive issues including a U.N. Security Council resolution that calls for all militias in Lebanon to be disarmed -- a demand supported by Hezbollah's Lebanese opponents.

Suleiman has been unwilling or unable to stop the Iranian- and Syrian-backed group from building up its arsenal and replenishing it after the 2006 war with Israel.

If Lebanon's sectarian tensions have tested the army's unity, its resources have also been stretched by the deployment of 15,000 soldiers in the south after the 2006 war and by prolonged battles with Islamist militants in the north in 2007.

Suleiman, a Maronite Christian from the village of Amchit, oversaw the deployment in the south under a U.N. resolution which halted the Hezbollah-Israel war.

The presidency is reserved for a Maronite under Lebanon's sectarian power-sharing system.

Suleiman's profile as a national figure soared during 15 weeks of fighting between the army and al Qaeda-inspired Islamist militants who launched an insurrection in the north a year ago.

Lebanese rallied around the troops during their campaign against the militants in a Palestinian refugee camp. More than 420 people, including 169 soldiers, were killed in the fighting before the revolt was put down.

Fluent in English and French, Suleiman is married with three children. He graduated from the Military Academy in 1970 and holds a Lebanese University degree in politics and administration. (Editing by Andrew Roche)

AlertNet news is provided by