The head of Cuba's central bank has resigned as President Raul Castro pushes ahead with a government reorganisation amid signs of a cash crunch, state television has reported.

Francisco Soberon, 64, has been replaced by Ernesto Medina, who heads Banco Financiero Inter-nacional, one of Cuba's biggest banks, according to an official announcement read on the evening news.

It did not say when the move had taken effect.

Soberon, who led the bank for nearly 15 years, also asked to be removed from the Cuban Communist Party's policy-making Central Committee and as a parliament deputy, it said.

Liquidity problem

The statement offered no explanation for his resignation but recent restrictions placed on large cash withdrawals suggest a liquidity problem on the island.

Soberon is known for carrying out the monetary policies of Castro's older brother, Fidel, who resigned from the presidency last year because of health problems.

In recent years, he oversaw the introduction of the Cuban convertible peso, which replaced the United States dollar as Cuba's legal tender.

The peso's value is tied to a basket of foreign currencies, including the dollar and the euro.

Cuban Foreign Minister Felipe Perez Roque and Vice President Carlos Lage were removed from the Cabinet in a stunning shake up in March.

At the time, state media published letters that both men had written to Raul Castro, acknowledging they had committed errors and promising to continue to serve the country.

Since then, several other Cabinet members have also lost their jobs as a large scale streamlining effort fused ministries that were deemed to have similar, overlapping tasks.