Yard 21, a former railroad switching yard that the city acquired from the MBTA for $3.1 million last year, is one of three parcels that comprise the proposed Assembly Square Common. Taurus and its partner, Gravestar, already own the other two parcels.

City officials here are hopeful that the successful disposal of Yard 21 will revitalize the stalled development of Assembly Square Common and, in turn, the larger Assembly Square project.

Taurus' plans for a Home Depot-anchored Assembly Square Mall, which wereapproved by city authorities last year, have been on hold for the past seven months because of a legal action against the development by a local resident. IKEA, the Swedish furniture chain, continues to revise its plans to win city support to develop a store on a 17-acre parcel it owns at Assembly Square.