For the first time in history, the landmark Transamerica Pyramid at 600 Montgomery is up for sale, although the Transamerica Corporation is being careful to maintain naming rights on the building that is so central its brand that it in fact doubles as the company logo.

That’s according to the San Francisco Business Times, which broke the story of the pending listing late Thursday and predicted a sale price of around $600 million, with the addition of two additional Sansome Street buildings included in the deal.

This heads off a longtime plan by the company to instead sell slightly less than half of the building, an investment scheme that in the end yielded no takers and led simply to a full-scale sale.

When completed in 1972, the 853-foot building was not only the tallest in the city but also the tallest west of the Mississippi, although only a few years later an LA tower surpassed it.

The pyramid remained San Francisco’s highpoint until the completion of Salesforce Tower just last year. Indeed, for a generation after the pyramid’s completion it seemed the city might never allow another edifice of these proportions again.

At the time the Transamerica building was deemed highly controversial, critiqued as too disruptive to the city’s skyline. The tapered “pyramid” shape by William Pereira & Associates was actually a concession to those who worried about the shadow it would cast on nearby streets, an attempt to narrow the tower’s profile at the highest points.

(These days the Transamerica Corp’s marketing language calls this “environmentally sensitive planning.”)

Before the pyramid building, the company worked out of the same Columbus and Montgomery office space now occupied by the Church of Scientology in North Beach.

At the time, the transition from an overwhelmingly neoclassical structure to a soaring maximal modern one was meant to signal a transition for the insurance corporation from the past to the future, but for a while it (accidentally) ended up touching off future shock for the whole city.