BOSTON >> The Citgo sign that lights up the Boston skyline is seen by baseball fans across the nation every time a home run sails over Fenway Park's left-field wall.
It's a comforting beacon for Boston Marathon runners who know they're nearing the end of their 26.2-mile ordeal when they see it.
Now there's fear it may soon be gone.
The six-story building on which the 3,600-square-foot sign, with its three-tone red delta and blue "Citgo" on a white background, sits is part of a parcel of Boston University buildings for sale, sparking fears that new owners could remove or relocate the sign that's visible from so many vantage points that people literally use it to navigate.
"For us, the sign makes us think of the Red Sox, but for people outside the city, it means Boston," said Greg Galer, executive director of the Boston Preservation Alliance , which is circulating an online petition to have the sign declared a landmark, which would offer some protections from change. "Whenever you see montages of Boston in movies, the sign is always included."
The petition had more than 4,700 signatures as of Friday.
The sign is also worth saving because it's a prime example of 1960s abstract pop art, said Arthur Krim, a Citgo sign expert who teaches historic preservation at Boston Architectural College.
The 12-member Boston Landmarks Commission meets Tuesday to decide whether to launch a study to determine if the sign qualifies as a landmark. To be designated a landmark, a property must have historic, social, cultural, architectural or aesthetic significance.
Getting listed isn't easy and could take months. Only about 100 sites in the city have earned landmark status. In fact, the Citgo sign was previously denied the designation in 1983.
Boston University had no comment on the sale or the future of the sign.
But in a story that appeared in an online university story in January, Robert Donahue, vice president for government and community affairs, said any development of the properties would be subject to approval by the city and the community.
A sign from what is today known as Citgo Petroleum Corp . has been part of Boston's cityscape since 1940. The current sign dates to 1965.
It has survived several hurricanes and prior attempts to permanently extinguish its lights.
The sign went dark for several years starting in 1979 at the height of the energy crisis, and in 1982 Citgo announced plans to dismantle it. The sign stayed after an uproar from Bostonians.
It has been refurbished several times, most recently in 2010 when electricians replaced about 218,000 LED lights with brighter, more energy-efficient and weather-resistant versions.
The bottom line is that it may be saved by its own fame. Who wants to be known as the person who tears it down?
"It's part of the fabric of the city," said Ted Tye, managing partner for National Development, a real estate developer not bidding on the property.
"I would think that you would take a lot of heat if you took it down."