SEVERODVINSK, April 8 (RIA Novosti) - The Sevmash shipyard in northern Russia said on Wednesday it would start construction of a fourth Borey class nuclear-powered strategic submarine this year.

"Russia's Defense Ministry has ordered the shipyard to start construction of the fourth Borey class submarine this year," a Sevmash official told RIA Novosti, adding that work could begin either in July or December

The first Borey class submarine, the Yury Dolgoruky, will start sea trials in June.

The vessel is 170 meters (580 feet) long, has a hull diameter of 13 meters (42 feet), a crew of 107, including 55 officers, a maximum depth of 450 meters (about 1,500 feet) and a submerged speed of about 29 knots. It can carry up to 16 ballistic missiles and torpedoes.

Two other Borey-class nuclear submarines, the Alexander Nevsky and the Vladimir Monomakh, are currently under construction at the Sevmash shipyard and are expected to be completed in 2009 and 2011. Russia is planning to build eight of these submarines by 2015.

All Borey class submarines will be equipped with new Bulava-M (SS-NX-30) intercontinental ballistic missiles, which carry up to 10 nuclear warheads and have a range of 8,000 kilometers (5,000 miles).