Under the agreement, the funds will be directed to humanitarian projects including hospital construction in the vast African state wracked by civil war for nearly 30 years.
A Swiss Foreign Ministry official said the accord, which specifies that the money must be used to help "the most vulnerable people in Angolan society", was signed in Geneva on Tuesday by representatives of the two countries.
The funds, deposited in four bank accounts in Switzerland, were blocked in late 2000 when Swiss police launched an investigation into the activities of a French businessman acting as a middleman between Angola and Russia.
The businessman, Pierre Falcone, was suspected of involvement with Angolan officials in what was believed at the time to be an attempt to embezzle money being sent to Moscow as part repayment of the country's debt to Russia.
Under the accord, reached after negotiations that began in November 2003, the two countries will jointly oversee the programme for the disposal of the released funds and will appoint officials to approve the projects that will benefit.