With its days as a television broadcasting tower numbered, the company that owns Tokyo Tower wants to register it as state-designated cultural property, company officials said Thursday.

Nippon Television City Corp. said the 333-meter radio and television tower, the world's tallest iron tower, will mark its 50th anniversary in December 2008, making it eligible for registration.

It will cease to function as a transmitter in 2011, when analog broadcasting is replaced by terrestrial digital broadcasting. A new 610-meter tower to be built in Sumida Ward will handle digital broadcasts.

"In order to preserve the tower, we must bring in tourists, and it is vital to take special measures to attract people," said Yoshihiro Watanabe, a senior company official.

Tokyo Tower was completed in 1958 and became a symbol of Japan's postwar recovery and economic growth.

The Cultural Affairs Agency said the tower should have little trouble gaining approval as a cultural property.

"It is a building symbolic of Tokyo's skyline and is very well-known. It is also valuable in terms of its architectural history and qualifies for registration," an agency official said.

Last year, Nagoya TV Tower, which was built in 1954, was registered as a cultural property. The owner of Osaka's Tsutenkaku Tower, which was completed in 1956, is also applying for cultural recognition.