"I understand it's done," says one downtown broker familiar withthe deal. The source estimates the lease at 90,000 sf, maintainingthat Viant will be taking the last major piece of 400,000 sf leftby Blue Cross and Blue Shield of Massachusetts. The health insurer,which owned half the building before selling its share to EquityOffice Properties, is relocating across town to new headquarters inthe Fenway District.

Calls to Viant Corp. were not returned by press deadline, whilean Equity spokeswoman declined comment on the matter. Nonetheless,sources say the deal has been cemented, with one broker placing therental rate at more than $60 per sf. Since buying the property in1998 for $222.5 million, Equity has undertaken an extensiveoverhaul of the 32-story, 1.06 million-sf tower. Most of the BlueCross space was snapped up earlier this summer by FidelityInvestments, which leased approximately 200,000 sf there.

Viant is currently located in a class B building on SouthStreet, a few blocks away from 100 Summer St. The company saw itsstock plummet by 42% last week after reporting its quarterlynumbers would be below expectations.