FACTBOX: Leadership changes in Cuba

(Reuters) - Cuba's acting President Raul Castro is expected to be confirmed as Cuba's new head of state by the National Assembly on Sunday, following his ailing brother Fidel Castro's retirement.

The following are possible leadership scenarios when the assembly ratifies the 31-member Council of State, Cuba's top executive body:

RAUL CASTRO

* Raul Castro, 76, the world's longest-serving defense minister and acting president since his brother fell ill in July 2006, is formally made president and head of state. This includes the prime-ministerial role as cabinet president. No surprises. Raul has run the country for 19 months.

* The baton could, in theory, be passed on directly to a younger leader, such as Vice President Carlos Lage, 56, as the new head of state. Most Cuba watchers doubt such a big change will occur in the leadership vacuum left by Fidel Castro. Raul gives the new government more legitimacy and continuity.

FIDEL CASTRO

* Fidel Castro told Cubans on Tuesday he was no longer well enough to govern and would soldier on in the "battle of ideas" through his writings. But he could still, theoretically, have a seat in the Council of State, as he is a deputy in the National Assembly. This was not considered likely, though, for the revolutionary icon.

* Fidel Castro continues to hold the powerful post of first secretary of the ruling Cuban Communist Party. He is expected to continue to lead the PCC until its next congress at the end of this year or the beginning of 2009. Health permitting, he will remain a key player, and king-maker behind the scenes.

OTHER FIGURES