New York -- The General Services Administration (GSA) on Wednesday announced plans to return to the World Trade Center in New York. The agency said it has signed a lease with the Port Authority of New York and New Jersey and the Durst Organization to occupy approximately 270,000 square feet on six floors at One World Trade Center. "There will once again be a federal presence in the World Trade Center, as there was from its beginning," said Dan Tangherlini, acting administrator of the GSA. Under the terms of the agreement, the GSA will occupy floors 50-55 of the building for an initial term of 20 years, beginning in 2015. One World Trade Center, initially known as the Freedom Tower, will be the third tallest building in the world, measuring 1,776 feet high, when it opens in 2013.