KHARTOUM (Reuters) - Sudan’s main opposition alliance will nominate Abdalla Hamdok, an economist who has served in international institutions, to be prime minister in the country’s transitional government, opposition sources said on Thursday.

The nomination is the first step toward the creation of a transitional government that will prepare for free elections after the overthrow of veteran autocratic president Omar al-Bashir in April following months of unrest.

The development came after protracted negotiations between the Transitional Military Council (TMC), which has ruled Sudan since April, and the opposition alliance known as the Forces of Freedom and Change (FFC).

A planned new sovereign council, comprised of five members each from the two sides plus a civilian agreed by both, will name the new premier based on the nomination by the FFC, according to a constitutional declaration agreed on earlier this month.

The sovereign council will be formed on Sunday, according to the agreed schedule, after which the Transitional Military Council will be dissolved, with the prime minister to be appointed on Tuesday next week.

Hamdok, long rumored as the FFC nominee, was last working as Deputy Executive Secretary of the U.N. Economic Commission for Africa, and has held positions at the International Labor Organization and the African Development Bank.

He served as an official in Sudan’s Ministry of Finance in the 1980s, before the military coup that put Bashir in power.

Sudanese economist Amin Hassan Sayed Ahmed said Hamdok had good connections in the African Union and United Nations and might help get Sudan removed from the U.S. list of state sponsors of terrorism, which has impeded Khartoum’s access to IMF and World Bank funding.

“I think he knows how to get in through the system, much more than anyone else who tried before,” said Sayed Ahmed.

“We wish Dr. Abdalla Hamdok success in one of the hardest periods in the history of our country and people, a period that the revolutionary Sudanese people are looking forward to and observing with hopefulness,” the Sudanese Professionals Association, the group that spearheaded the protest movement and is part of the FFC, said in a statement.

The opposition alliance will also nominate former judge and human rights activist Mohamed Alhafiz Mahmoud as public prosecutor, opposition sources said, and Abdelqadir Mohamed Ahmed as head of the judiciary.

In a press conference on Thursday night, a representative of the FFC said their nominees for the two positions had been delivered to the Transitional Military Council, and their appointments were expected within the next 24 hours.

The FFC and Transitional Military Council are expected to put final signatures on the constitutional declaration on Saturday at a ceremony in Khartoum with foreign dignitaries attending.

Some caution that it is still too early to tell how events will unfold in the lengthy, three-year, three-month transition period agreed to prepare for elections after three decades of repressive rule under Bashir.