The Swedish firm Skanska on Friday won a contract to serve as the leading construction manager to renovate the United Nations headquarters in New York, according to dpa. The renovations are to cost about 2 billion dollars when completed. Skanska was selected in a competitive bidding process, a major step by the UN to begin the renovation of the 1950s-era facility. New York City authorities have said the facility now violates all US building codes, from fire extinguishers to building materials. New York City Mayor Michael Bloomberg earlier visited the headquarters to request that the renovations meet environmental requirements in the city. UN Undersecretary General for Management Alicia Barcena, who signed Skanska, said the firm will review the current design drawings and look for cost savings opportunities. "The signing of this agreement is a major step in making the UN headquarters a safer, healthier, more secure and more energy efficient place for all of us who work here - staff, diplomats and even journalists," she said in announcing the contract with Skanska. The UN headquarters employs more than 4,000 people from all 192 countries that are UN members. Foreign missions accredited to the UN maintain separate offices and residences scattered across New York City, making it the world's largest diplomatic community with more than 40,000 diplomats, their families and office workers. The Stockholm-based Skanska employs 56,000 in markets in Europe, the United States and Latin America. Its sales in 2006 totaled 17 billion dollars.