SAN FRANCISCO (Reuters) - Tony Bennett, who 50 years ago recorded his signature song "I Left My Heart in San Francisco," will be the northern California city's toast of the town on Valentine's Day, officials said on Friday.

The 85-year-old singer first performed the song in December 1961 at San Francisco's Fairmont Hotel. He recorded it the next month and it became a hit single and eventually turned into his most famous number.

"Performing 'I Left My Heart in San Francisco' in the Venetian Room at the Fairmont Hotel was one of the most fortunate moments of my career," Bennett said in a statement.

Joining Bennett and Mayor Ed Lee at San Francisco City Hall on Tuesday for Valentine's Day will be U.S. Senator Dianne Feinstein and House Minority Leader Nancy Pelosi, among others.

A sing-along of the famed tune is planned, and officials have asked San Francisco-area radio stations to play it at noon. Public address systems in the city's Union Square and Hallidie Plaza will blare the music, officials said.

(Reporting by Emmett Berg: Editing by Alex Dobuzinskis and Cynthia Johnston)