HOLGUIN, Cuba (Reuters) - The Cuban Communist Party has moved forward the election of new leadership to a congress in April where longtime party leader Fidel Castro is expected to step down, sources close to the party said over the weekend.

Castro, 84, previously handed over most of the responsibilities as first secretary but kept the title. His official departure from his last leadership position would be a symbolically important step toward a new era for the island he ruled for 49 years.

President Raul Castro, as second secretary of the Communist Party, is in line to succeed his older brother as its top leader, just as he did when Fidel Castro resigned the presidency in February 2008.

But because there are currently no other Castro family members in leading positions, the second secretary spot likely will be filled by someone without Castro as a last name for the first time since the party was created in 1965.

As first and second secretaries, the Castro brothers lead the party's guiding Central Committee, for which elections originally were expected to be held at a party conference at the end of this year. But the vote has been moved to April because party statutes say it must be done at a formal congress, sources said.

The Central Committee chooses the party's powerful Political Bureau and its executive Secretariat, where numerous changes are also expected, sources said.

Governments, Cuba watchers and the local population hope changes in the top party ranks will shed light on who might replace the Castro brothers and other aging leaders who first came to power in the 1959 revolution in which Fidel Castro took over the Caribbean island.

At stake is the future leadership of the country as it undergoes important economic reforms that President Castro, 79, says are necessary to keep the communist system alive.