The leader of the 19 defectors, Lt. Col. Okello Okutti, was abducted by the LRA in 1989 and had risen to prominence within the group, the statement added.
Late last month, a senior LRA commander and 13 of his rebel fighters were killed by Ugandan forces in the Central African Republic.
Col. Samuel Kangul, believed to be the fourth in command of the LRA ,was killed using intelligence gathered by United States advisers, said Ugandan Army Deputy Spokesman Maj. Robert Ngabirano.
About 100 U.S. Special Forces are helping African troops to hunt down LRA leader Joseph Kony, who is wanted by the International Criminal Court for war crimes and crimes against humanity.
Kony's LRA is accused by the United Nations and human rights groups of killing and mutilating innocent civilians and kidnapping thousands of children, forcing them to be soldiers and sex slaves.