US manufacturer of industrial, process and specialty gases Praxair bought Volga Azot industrial gas producer from Russia\'s largest petrochemical group Sibur, Praxair said on Monday without disclosing the amount of the deal. The purchase of Volga Azot based in the Volgograd region in country\'s south is the fourth largest investment of Praxair in Russia. The Russian subsidiary of the company has invested nearly $250 million in the country\'s facilities since 2008. The overall capacity of projects implemented by Praxair in Russia exceeds 3,500 tons of gaseous and liquid oxygen, nitrogen, hydrogen and argon per day. President of Praxair Europe Todd Skare was quoted in the company\'s statement as saying that the Volga Azot purchase broadened sales opportunities of the company and created conditions for Praxair to become a leading industrial gases producer in Russia\'s south.