Maria Jose, one of the 10-month-old Siamese twins separated last week in an operation that took 20 hours to perform, died over the weekend of cardiac problems.

The little girl died Sunday at 8:15 of a "multiple organic failure associated with her cardiac problems," Luis Calvo Mackenna Children's Hospital director Osvaldo Artaza said.

Maria Jose, who was separated from her twin, Maria Paz, last Wednesday, had been in a critical state and in danger of dying, as Artaza warned several days ago.

Soon after the operation, the baby suffered extreme tachycardia and in the following days had to be revived on several occasions.

As to the state of her sister's health, Artaza said that doctors have "great hopes for Maria Paz's survival despite her grave condition."

The baby remains in stable condition with no change in her basal and metabolic parameters, and following the dialysis she needed this weekend, her kidneys have begun to function, Artaza said.

Before being separated, the baby girls, born in the southern region of La Araucania, had undergone seven previous surgeries, the last to separate a leg they shared.

Separated during the marathon operation this week were the livers, large intestine and anus that they also shared.