ST. PETERSBURG, November 29 (RIA Novosti - North-West, Anna Novak) - The St. Petersburg-based Admiralty Shipyard has begun sea trials of a fourth-generation Project 677 Lada class diesel-electric submarine, the company's press office said Tuesday.

During the next few months, the submarine, called St. Petersburg, will undergo maneuverability and submersion tests and operation in extreme conditions. The latest technological advances were used to create the submarine's main energy unit and other systems.

After comprehensive testing, the submarine will be transferred to the Russian Navy, the company said.