Vice Admiral Konstantin Sidenko will be appointed commander of the Pacific Fleet and Vice Admiral Viktor Mardusin will become commander of the Baltic Fleet, the source said.
"Both appointments have been approved, and respective orders will be issued in the next few days," the source, who asked to remain anonymous, said.
Sidenko, 53, is currently commander of the Baltic Fleet, and Mardusin, 49, is the Pacific Fleet's chief-of-staff.
The Russian Navy is composed of the Northern Fleet, the Pacific Fleet, the Black Sea Fleet, the Baltic Fleet, the Caspian Flotilla, Naval Aviation, Naval Infantry (marines) and coastal artillery.
Defense Minister Anatoly Serdyukov said in August that the entire Navy leadership would be reshuffled by the end of 2007 to ensure the Navy's future development and strengthen the combat readiness of naval forces.
Earlier this year Admiral Vladimir Vysotsky, 53, replaced Admiral Vladimir Masorin as Navy Commander, while Vice Admiral Alexander Kletskov, 52, was appointed commander of the Black Sea Fleet and Vice Admiral Nikolai Maksimov, 51, became commander of the Northern Fleet.
Russia's current naval strategy continues to focus on the development of its strategic naval nuclear forces. Fourth-generation Borey-class nuclear submarines armed with Bulava-M ballistic missiles would form the core of the submarine fleet. The first submarine of the series, Yury Dolgoruky, is expected to join the Navy in 2008.
Russia has also made a decision to start serial production of the Bulava-M missile, following a successful test launch in late June.