Haiti's prime minister resigns after four months PORT-AU-PRINCE (Reuters) - Haitian Prime Minister Garry Conille resigned on Friday after just four months in office, plunging the country into political paralysis in the midst of rebuilding efforts two years after a devastating earthquake. Conille submitted his resignation in a letter to President Michel Martelly, according to a statement by the president's office. There was no immediate word on a possible replacement. Conille's decision to step down came during political infighting between the two leaders over earthquake reconstruction contracts, as well as a parliamentary investigation into dual citizenship of government ministers, which is illegal under Haitian law. Conille, a 45-year-old medical doctor and U.N. development expert, was popular with foreign aid donors and many members of the international community involved in Haiti's reconstruction efforts after a January 2010 earthquake shattered the country, killing more than 200,000 people. He previously served as chief of staff of the U.N. Office of the Special Envoy to Haiti, led by former President Bill Clinton. In a brief nationally televised address, Martelly said he had spoken with parliamentary leaders and "we committed to meeting soon to propose a new prime minister." The U.S. Embassy in Haiti issued a statement calling for the "swift" appointment of a successor to ensure political stability, while expressing "regret" over Conille's departure. Political tensions between Martelly and Conille erupted recently after Conille announced plans to audit $300 million in contracts awarded by his predecessor after the earthquake. Conille and members of his Cabinet were also under pressure to cooperate with a parliamentary commission investigating the nationalities of members of the government. Conille and some of his aides have held jobs and lived for extended periods outside Haiti. Critics say Conille also alienated parliament and the president, including members of his own Cabinet, by some of his actions. "It didn't work from day one," said Alice Blanchet, a special adviser to five former prime ministers, including Conille's predecessor, Jean-Max Bellerive. She described Conille's questioning of the earthquake reconstruction contracts as "petty and unpatriotic," noting that no irregularities had been identified by the international community. "That was offensive to parliament and to the president," she said. The resignation could set the stage for another political showdown between Martelly, who took office in May 2011, and lawmakers in parliament, where he does not hold a majority. Conille's appointment as prime minister in October came after a five-month delay during which Martelly's first two nominees were rejected, impeding his ability to assemble a government to move ahead with reconstruction efforts. It's so frustrating. It reflects once again the willingness of political figures in Haiti to let policy differences reach the point of total polarization and stalemate," said Mark Schneider, vice president at the International Crisis Group, a Washington-based think tank that monitors Haiti closely. "We are now embarked on another unknown journey of unknown length to try and find another prime minister," he added, noting how long it took Martelly last year to find a candidate acceptable to parliament. "These things in Haiti are so destructive," he said. For a country that is barely keeping it's head above water, this is like picking up another rock that pulls you further down to the bottom. Two years after the quake, more than a half a million people are still living in tent camps in the capital, Port-au-Prince, and piles of concrete, steel and debris litter the streets. During a recent visit to Haiti, U.S. Ambassador to the United Nations Susan Rice called on the country's political leaders to stop bickering. "Haiti's executive and legislative branches," Rice said, "need to rise above their interests and work together in the spirit of compromise and overcome their common challenges." Her words were echoed on Thursday by Mariano Fernandez, head of the U.N. peacekeeping mission in Haiti. Fernandez issued a statement expressing concern that "the political deadlock and institutional paralysis between the government, parliament and the president ... are not likely to create the necessary conditions for recovery of the economy and the consolidation of democracy." Additional reporting by David Adams in Miami; Writing by Kevin Gray; Editing by Peter Cooney