Sources tell GlobeSt.com that Normandy has emerged the top bidder for 273, 281 and 321 Summer St., reportedly paying close to $75 million for the 270,000-sf package.

Calls to Normandy officials were not returned by press deadline, while a broker for the seller, Archon Group LP, declined comment. That broker, Coleman Benedict of Holliday Fenoglio Fowler, would neither confirm nor deny that a deal had been struck. Others said to have competed hard for the properties include Everest Partners LLC and a partnership of AEW Capital Management and Saracen, two local players who teamed up last year to buy One Washington Mall in downtown Boston.

Sources could not say precisely what price Normandy bid, or how far along in the process the deal is, but several insisted that the firm has the buildings under agreement. "That's definitely the case; they do have it tied up," claimed one broker. Another source maintained that Normandy is paying at least $73 million and possibly upwards of $275 per sf, a figure that would equal $74.2 million. If the sale does reach or exceed $275 per sf, one source characterized the number as "frightening," especially given the condition of the conjoined 273 and 281 Summer St. buildings, which will require extensive renovation to lease as market-rate office space.

Unlike 99 Summer St., which abuts other Downtown towers such as One Lincoln St., the current Summer Street targets are sited in the city's ancient Fort Point Channel district, in which rents have traditionally been much lower. But while observers say the price per pound apparently being offered by Normandy could require rents in the $40-per-sf range to achieve minimal returns, Fort Point Channel has traditionally struggled to achieve $30-per-sf deals. According to first quarter figures from Jones Lang LaSalle, the submarket is currently averaging triple net rents of $27.92 per sf compared to $45.82 per sf in the Financial District.

On the flip side, observers note that the district is again benefiting from those rising rental rates in the Financial District and Back Bay, a condition that has previously led to surges of tenants crossing from Downtown to find relief. Landlords have also responded by fixing up older buildings enough to raise rates, with observers maintaining that the 321 Summer St. building in the package has done well on occupancy and rental rates since it was converted from a vacant warehouse building earlier this decade. That property was one of 17 in the district purchased in 2005 by Archon LP. The Texas-based investor has subsequently been selling off several of those properties, earlier this year divesting 311 Congress St. to ADD Inc., a Cambridge architectural firm that is moving 160 employees to the building.

ADD Inc. is one of several architectural and professional services firms that have embraced the historic feel of Fort Point Channel, Boston's top manufacturing district from the 1800s into the 1970s. In another rumor, sources claimed Archon is also selling 268 Summer St. to Normandy for an undetermined price. That asset was acquired prior to the portfolio deal in 2005 and is being marketed separately, with Richards Barry Joyce & Partners said to have that listing. Calls to RBJ's investment services group were not returned, and it is unclear what the status of that deal is at present.

Normandy has become an active player in Greater Boston during the past few years after having no holdings in the region. Initially buying into the Waltham, Lexington and Concord markets, the company last month paid a record price of about $338 per sf for 4 van de Graaff Dr. in Burlington. That $33-million sale, first reported by GlobeSt.com, was negotiated by JLL's Boston investment sales team.