Haitian President Rene Preval nominated his longtime friend and adviser Robert Manuel on Sunday to become prime minister of the impoverished Caribbean nation, where the previous government was toppled by food riots in April.

Preval named Manuel in a late-night meeting with the presidents of the Senate and Chamber of Deputies, the lower house in Haiti's parliament. Both chambers must vote on the nomination.

Preval's efforts to establish a stable democracy in Haiti were dealt a heavy blow when violent demonstrations erupted last month over the rapidly escalating cost of living in the poorest country in the Americas.

At least six people were killed in the protests, which spread from the southern city of Les Cayes to the capital, Port-au-Prince, and other towns and cities.

Shortly after the riots, the Senate fired then-Prime Minister Jacques Edouard Alexis. Parliament rejected Preval's first nominee to replace Alexis, Inter-American Development Bank official Ericq Pierre, on May 12.

Manuel, 55, is an architect and a recognized security and law enforcement authority who served as secretary of state for public safety during a portion of Preval's first term as president from 1996 to 2001. He managed Preval's successful election campaign in 2006.

"I believe we need to work together to change this country and I want to make my contribution," Manuel told Reuters following his nomination.

Pierre's candidacy was rejected in a 51-35 vote in the lower house a few days after the Senate approved his nomination. Deputies who voted against him said he had failed to provide proof required under the constitution that he is descended from native-born Haitians.

Lawmakers were expected to begin discussions on the new nominee on Monday.

"The Coalition of Parliamentarians for Progress has set up a meeting tomorrow (Monday) to determine what its position will be," said Levaillant Louis-Jeune, a spokesman for the group of lawmakers that joined to defeat Pierre's nomination.

Haiti has seen little but political upheaval and brutal dictatorship since it threw off French rule in a slave revolt more than 200 years ago.

It stands among a number of poor countries rattled in recent months by violence over escalating food prices blamed on growing demand in Asia, diversion of crops for biofuel, record oil prices and market speculation.

Poor Haitians say the cost of staples such as rice, beans and flour has doubled in the past few months.

Preval, who took office in May 2006, is the only elected Haitian leader to serve a full term and successfully hand over power to a democratically elected successor.

But he has been the subject of increasing criticism for the perceived failure of his government to increase food production and lower living costs.

In his first term, it took Preval 21 months to put a new government in place after then-Prime Minister Rosny Smarth resigned in June 1997.