By Marc Frank

HAVANA (Reuters) - Cuban leader Raul Castro announced on Sunday he would step down from power after his second term as president ends in 2018.

Castro made the announcement in a nationally broadcast speech shortly after the Cuban National Assembly elected him to a second five-year term in the opening session of the new parliament.

In a surprise move, the new parliament named a rising young star as his first vice president, Miguel Diaz-Canel, 52, a member of the political bureau who rose through the party ranks in the provinces to become the most visible possible successor to Castro. Diaz-Canel would succeed Castro if he cannot serve his full term.

Raul Castro, 81, who officially replaced his ailing brother as president in 2008, has repeatedly called for senior leaders to hold office for no more than two, five-year terms.

He starts his second term immediately. In 2018, Castro will be 86.

(Editing by David Adams and Stacey Joyce)