Syria's rebel coalition has elected as its prime minister Ghassan Hitto, a little-known American-educated IT manager and Islamic activist who will head an interim government to administer the areas seized by opposition forces from the regime troops of President Bashar Assad.

Hitto received 35 votes out of 48 ballots cast by the opposition Syrian National Coalition's 63 active members during a meeting in Istanbul. The results were read aloud by coalition member Hisham Marwa to applause from a few dozen of his colleagues who had waited until after 1am to hear the results.

"I miss my wife and children and I look forward to seeing them soon," said Hitto, who has lived in the United States for decades and recently moved from Texas to Turkey to help co-ordinate aid to rebel-held areas.

When asked what his interim government's first priority would be, Hitto said he planned to give a speech later on Tuesday outlining his plans.

Hitto did not receive a resounding mandate from the coalition, of which he is not a member. Of the group's 63 active members only 48 voted. Four cast blank ballots and Hitto received 35 of the remaining votes.

Hitto was born in Damascus, the Syrian capital, in 1963, according to his official resumé provided by the coalition. Little known in Syria, Hitto has lived in the United States for more than two decades, most recently in Texas. He has academic degrees from Purdue University in Indiana and Indiana Wesleyan University.

He worked for a number of different technology companies and helped run a Muslim private school called the Brighter Horizons Academy. He is also a founding member of the Muslim Legal Fund of America, which was founded to give legal aid to Muslims following the 9/11 terrorist attacks. He is married with four children.

Coalition members hope the new government will unite the rebels fighting Assad's forces on the ground and provide services to Syrians living in rebel-held areas, many of which have been battered by the country's civil war and suffer acute shortages of food, electricity and medical services.

But the new government faces huge challenges, starting with its ability to gain recognition from rebel factions on the ground.

As rebels have progressed in northern and eastern Syria, a patchwork of rebel groups and local councils have sought to fill the void left by the government's withdrawal by organising security patrols, reopening bakeries and running courts and prisons. It is unclear if these groups, many of which have taken charge of their own towns, will accept an outside authority, especially if it is headed by someone who has spent decades abroad.

"How can a civilian come and tell these fighters on the ground: 'Drop your weapons, it's my turn to rule'?" asked Adib Shishakly, the coalition's representative to a group of Gulf nations known as the Gulf Co-operation Council, before the results were announced.

Hitto's election follows two attempts that failed to form interim governments due to opposition infighting. Coalition members say they received insufficient international support to allow them to project their authority to groups inside Syria. The new government could have the same problem.

"You have to find a way to co-operate with these groups and you can only rule by providing services, which requires funding," Shishakly said.

The US has been cool to the idea of a rebel government to rival Assad's and supports a peace plan put forward by the UN and the Arab League that calls for the formation of a transitional government that represents the regime and the opposition.

The UN secretary general, Ban Ki-moon, has reiterated his call for a political solution "while there is still time to prevent Syria's complete destruction".

On Monday the US secretary of state, John Kerry, said the Obama administration wanted to leave the door open for a political solution. Regarding the rebels he said the US would not "stand in the way of other countries that made a decision to provide arms, whether it's France or Britain or others".

The French president, François Hollande, has said his country and Britain are pushing the European Union to lift its arms embargo on Syria so they can arm the rebels. Germany and other EU nations oppose the move, saying it will exacerbate the violence.

Coalition members in Istanbul rejected the idea of negotiating with the Syrian government before Assad leaves power. "We've heard a lot about this peaceful solution but there are no positives, real steps from the regime," said Nizar Al Hrakey, a coalition member.

On Monday the head of Syria's largest official rebel group, the Free Syrian Army, threw his weight behind the idea of an interim government. "We consider it the only legal government in the country," General Salim Idris told reporters in Istanbul.

Idris's authority within the country remains limited, with some of the most successful rebel groups on the ground rejecting his authority.

The Syrian government did not immediately comment on the Istanbul meeting. It says the war is the result of a foreign conspiracy to weaken Syria.

Activist Ghassan Yassin, who watched the vote after travelling from the embattled city of Aleppo, said he saw "no reasons to be optimistic about the formation of an interim government".

He said he had only heard of Hitto recently and doubted his government would have the resources to make a difference. "The question is not whether there is an interim government but whether there will be any support for it," he said.

On Monday Assad's fighter jets struck targets near the town of Arsal, Lebanon, according to Lebanon's state-run National News Agency. The two countries share a porous border. A US state department spokeswoman confirmed Syrian warplanes and helicopters had fired rockets into northern Lebanon, striking near Arsal in a "significant escalation in violations of Lebanese sovereignty".