Martelly’s designation of Garry Conille, 45, a medical doctor who had served as aide to former US President Bill Clinton in the latter’s role as special UN Haiti envoy, followed the rejection by Haitian lawmakers in June and August of two nominees.

These rejections have blocked the formation of a new Haitian government four months after Martelly, a former pop star, took office with a public promise to turn the Western Hemisphere’s poorest state into a Caribbean success story.

Haiti, which has gained a reputation as a development basket case after decades of dictatorship, corruption and instability, faces a huge reconstruction task after last year’s catastrophic earthquake and a continuing cholera epidemic.

“It is now official. Garry Conille is the new prime minister-designate. The letter has been sent to parliament,” Jean Renel Sanon, the secretary-general at the presidential palace, told Reuters.

The nomination, made in a letter to lawmakers on Monday, must be approved by both houses of Haiti’s Parliament. They are dominated by senators and deputies whose parties fielded rival candidates to Martelly in a turbulent two-round presidential election finally won by him in a March run-off vote.

The rejection by lawmakers of Martelly’s previous choices for premier — economist and businessman Daniel Rouzier and lawyer and former Justice Minister Bernard Gousse — raised concerns among diplomats and donors who say Haiti desperately needs a stable working government to rebuild from the quake.

Martelly has already held discussions with groups of lawmakers about Conille’s designation. But some parliamentarians have raised questions about his eligibility for the post because he has spent years outside the country, working for the United Nations.

Before his nomination, Conille was working as the UN Development Program’s resident coordinator in Niger.

Haiti’s constitution requires a candidate for prime minister to have spent five consecutive years in Haiti before taking up the post.

Some lawmakers said the residency issue should not be an impediment.

“There are international treaties signed by Haiti that allow functionaries working for the UN to maintain their residency in their original countries, and that should not be a problem for Mr. Conille,” Tholbert Alexis, who leads the majority group in the lower chamber of deputies, said.

“You can travel the world working for the UN on diplomatic missions and still reside in your country,” he said in comments to local radio.

But others saw the residency question as a problem.

“If my lawmaker colleagues want to vote for him (Conille) on the basis of political considerations, they may do so, but if they want to stick to legal requirements he will not be approved because he was not living in the country,” said one senator, Jean-Hector Anacacis.

Haiti’s Chamber of Deputies and Senate were expected to consider and vote on Conille’s nomination in coming days.

Haitian authorities estimate the January 2010 earthquake killed more than 300,000 people, and the disaster wrecked much of the capital, Port-au-Prince.

Pressing tasks for the new government include effectively fighting the cholera epidemic that has killed more than 6,000 people since October, and providing adequate shelter for tens of thousands of earthquake survivors who are still living in makeshift tent camps vulnerable to hurricanes and floods.