Central Bank First Deputy Chairman Andrei Kozlov, who oversaw bank licensing and led a campaign against corruption and money laundering, was shot dead along with his driver in September 2006. Kozlov had revoked the licenses of banks run by Frenkel.
The court sentenced the assassin, Alexei Polovinkin, to life in prison, and gave the other five defendants prison terms ranging from six to 24 years.
Bogdan Pogorzhevsky will have to serve six years in a high-security prison on charges of murder and illegal arms trafficking.
Restaurant owner Liana Askerova and Ukrainian businessman Boris Shafrai were found guilty to be accomplices in the murder and sentenced to 13 years in a general-security prison and 14 years in a high-security prison, respectively.
Frenkel has been in custody since January 2007, along with Askerova, whose testimony led to his arrest, and Shafrai.
Alexander Belokopytov, found guilty of murder but acquitted of illegal arms trafficking, was given 10 years.
Maksim Proglyada, Polovinkin's accomplice, was given 24 years in a high-security prison on charges of murder and illegal arms trafficking. Another suspect in the case is at large and on an international wanted list.
The court also collected a total of 10 million rubles ($363,000) from the guilty for a lawsuit filed by Kozlov's father.
Investigators earlier said Frenkel paid $300,000 for the murder, and that the perpetrators received between $3,000 and $8,500 with the intermediaries receiving over $80,000 each.
Frenkel said he will appeal the verdict.