Martin Ngoga, Rwanda's chief prosecutor, confirmed the new releases.
"This group will exclude key masterminds of the genocide," he said.
Human Rights Watch said this week that Rwanda faces a new round of ethnic violence if it fails to prosecute the killers of witnesses and survivors of the genocide.
It said dozens of survivors and others involved in the traditional gacaca court process have been killed in recent years.
Since 2003, Rwanda has released between 50,000 and 60,000 prisoners, of whom about 80 per cent were accused of involvement in the genocide. Hundreds have been re-arrested, however, after committing other crimes on reaching home, including killing genocide survivors in an attempt to destroy evidence.
The inmates to be freed next month will undergo a month-long civic "sensitisation" programme before being allowed to go to their homes, Ngoga said.
About 800,000 members of the minority Tutsi ethnic group and moderate Hutus were butchered in 100 days of killings from April 1994 blamed on Hutu hardliners.