Bank of America Plaza, the tallest building in metro Atlanta, is going on the auction block Tuesday.

The 55-story, 1,023-foot building will be sold  on the steps of the Fulton County Courthouse after landlord BentleyForbes missed mortgage payments.

The California-based commercial real estate investment firm bought the tower at the height of the real estate boom for an Atlanta-record $436 million. It has been working to avoid default.

The main $363 million loan on the tower went to a special servicer LNR Partners in February, while a second loan had been in default for nonpayment.

The foreclosure of Bank of America Plaza comes as delinquency rates for commercial mortgage backed securities, or CMBS, a type of loan for commercial properties, reached an all-time high in metro Atlanta in December, according to Trepp, a real estate research firm.

With a $12.8 billion CMBS balance outstanding, $2.73 billion, or 21.3 percent was 30-plus days delinquent or worse -- compared with 13.2 percent in December 2010, Trepp said.

If a buyer could snap up the tower at a major discount, they could offer space at below market rent -- a major competitive advantage, said Ronald Glass, a principal at GlassRatner Advisory & Capital Group.

"There is a lot of capital on the sidelines ... looking for opportunities," Glass said.