A dozen well-known developers have submitted proposals to build a 550,000-square-foot office building on Massachusetts Port Authority’s parcel A-2, one of the last available development sites in the core of Boston’s Seaport District.

The 1.1-acre site, currently used as surface parking, is next to the MBTA’s World Trade Center station on the Silver Line.

Massport sought proposals for a “signature office development” on the property, including an option for a 11,500-square-foot air rights section above the Massachusetts Turnpike’s exit 25 off-ramp, which runs along the southern side of the site. Massport encouraged developers to make diversity a priority while assembling the project teams.

The list of respondents announced Thursday includes Accordia Partners, Boston Global Investors, Chiofaro Co., City Point Capital, The Davis Cos., Leggat McCall Properties, Lincoln Property Co., Longfellow Real Estate Partners, Peebles Corp., Redgate Holdings, Skanska USA and WS Capital Partners, Massport spokeswoman Jennifer Mehigan said.

FAA restrictions limit building heights to 269 feet on the site.