WASHINGTON - Haiti needs $11.5 billion over three years to rebuild after January's earthquake devastated one of the world's poorest countries, a World Bank and United Nations estimate found Tuesday.

The sum is a tentative estimate of the cost to rebuild crushed infrastructure and relaunch economic activity, said Sergio Jellinek, World Bank spokesman for Latin America and the Caribbean.

"This is a draft report. The recovery and reconstruction figure is still a work in progress," he told AFP, noting the figure does not address issues like double counting.

Jellinek said a final estimate would before an international donors conference set for March 31 in New York.

Last month, the Inter-American Development Bank, which is also contributing to the report, estimated that Haiti's recovery would cost $14 billion.

The January 12 tremor, which killed more than 220,000 people and left 1.3 million others homeless, reduced a large swath of the capital Port-au-Prince and other cities to rubble.