This post was written by Hatchet Staff Writer Ian Jannetta

Construction at Square 54 is slightly ahead of schedule, according to the project’s manager, but the identity of the grocery store that will fill a substantial amount of the project’s space remains a mystery.

In October, Boston Properties Senior Project Manager Jake Stroman said he had a letter of intent from a particular grocery chain to lease space in the mixed-use property. This month, lease negotiations are still underway with the grocery chain.

“Unfortunately, I can’t set a time table as to when we can report to have signed a lease,” Stroman said in an e-mail.

Workers continue to frame and pour concrete on the rising structures, Stroman said.

The office building currently stands more than six stories above street level in some areas. So far, only one lease has been signed, which will use 190,000 square feet of the development.

The law firm, Hunton & Williams, will take up 43 percent of the 450,000 square feet of office space, Stroman said.

The development will also include 84,000 square feet of retail space and more than 300 apartments.

Work on the office building remains slated for completion in early 2011, while the residential building will be completed a few months later.

The lane of 22nd Street between Eye Street and Pennsylvania Avenue that had been closed due to construction has re-opened, although periodic lane closures are possible until work is complete, according to the GW Neighborhood Web site.