The Russian Navy has maintained a presence off the Somali coast since October 2008, with warships operating on a rotation basis.
The latest Russian anti-piracy mission in the Gulf of Aden was carried out by a Pacific Fleet task force led by the Admiral Vinogradov destroyer.
During its four-month-long patrol duty, which ended on April 17, the task force successfully escorted 14 convoys of commercial vessels.
According to the UN, the number of pirate attacks on merchant ships reached 400 in 2010. A total of 790 sailors and crew members were captured by pirates last year.
Piracy off the Somali coast costs the international community up to $8.3bn (£5.1bn) a year, a new report from the Geopolicity consultancy estimates. That sum could reach $13-15bn by 2015, it says.
It calculates that a pirate can earn up to $79,000 a year.
"Given the supply and demand for piracy services... there is plenty of room for expansion," the report warns.

