Yamasaki ultimately settled on the idea of twin towers. To meet the Port Authority's requirement to build of office space, the towers would each be 110 stories tall. The size of the project raised ire from the owner of the Empire State Building, which would lose its title of tallest building in the world. Other critics objected to the idea of this much "subsidized" office space going on the open market, competing with the private sector. Others questioned the cost of the project, which in 1966 had risen to $575million. Final negotiations between The City of New York and the Port Authority centered on tax issues. A final agreement was made that the Port Authority would make annual payments in lieu of taxes, for the 40% of the World Trade Center leased to private tenants. The remaining space was to be occupied by state and federal government agencies. In 1962, the Port Authority signed the United States Customs Service as a tenant, and in 1964 they inked a deal with the State of New York to locate government offices at the World Trade Center.