stylistic:style_transfer, quality:correction, linguistic:voice_change, information:extraction
Loss of "tallest building" title

In 1961, the same year that Helmsley, Wien, and Malkin had purchased the Empire State Building, the Port Authority of New York and New Jersey formally backed plans for a new World Trade Center in Lower Manhattan. The plan originally included 66-story twin towers with column-free open spaces. The Empire State's owners and real estate speculators were worried that the twin towers' 7.6 million square feet (710,000 m) of office space would create a glut of rentable space in Manhattan as well as take away the Empire State Building's profits from lessees. A revision in the World Trade Center's plan brought the twin towers to 1,370 feet (420 m) each or 110 stories, taller than the Empire State. Opponents of the new project included prominent real-estate developer Robert Tishman, as well as Wien's Committee for a Reasonable World Trade Center. In response to Wien's opposition, Port Authority executive director Austin J. Tobin said that Wien was only opposing the project because it would overshadow his Empire State Building as the world's tallest building.

The World Trade Center's twin towers started construction in 1966. The following year, the Ostankino Tower succeeded the Empire State Building as the tallest freestanding structure in the world. In 1970, the Empire State surrendered its position as the world's tallest building, when the World Trade Center's still-under-construction North Tower surpassed it, on October 19; the North Tower was topped out on December 23, 1970.

In December 1975, the observation deck was opened on the 110th floor of the Twin Towers, significantly higher than the 86th floor observatory on the Empire State Building. The latter was also losing revenue during this period, particularly as a number of broadcast stations had moved to the World Trade Center in 1971; although the Port Authority continued to pay the broadcasting leases for the Empire State until 1984. The Empire State Building was still seen as prestigious, having seen its forty-millionth visitor in March 1971.