Rivertech Park is leased to a pair of new-age enterprises, one specializing in fuel cells and the other a supplier to the semiconductor industry. "It's a dynamic property and they have some great tenants," one broker familiar with Rivertech says in explaining investor interest in the park. Both Nuvera Fuel Cells and Entegris have long-term leases. Struck last year, the Nuvera lease marked a turnaround for Rivertech, a large portion of which had been vacant since the departure of CR Bard Manufacturing Co. in 2000. Nuvera agreed to relocate from Cambridge, spending $15 million to further upgrade the Rivertech space where it now houses hundreds of employees in 110,000 sf of office and manufacturing space.

Another key ingredient said to have driven pricing for Rivertech Park lies in the contributions of erstwhile tenant Nortel Networks, at the turn of the decade among the more promising technology firms active in suburban Boston. Trying to position 129 Concord Rd. as a facility worthy of the firm's high-tech mien, Nortel spent an estimated $10 million to soup up the complex with the latest in computer, electrical and mechanical capabilities. When Nortel was throttled by the technology crash, 129 Concord Rd. became expendable, leading to its sale to New Boston Fund in June 2002 for $23 million. As a result, "there aren't many buildings like it" in suburban Boston, says one broker who maintains that superior physical pedigree enticed Nuvera to make its commitment.

As for the sale to KBS, parties involved in the transaction are remaining silent. Calls to brokers on the deal at Eastdil Secured in Boston were not returned. A spokeswoman for NBF acknowledges that Rivertech is on the market, confirming Eastdil's involvement, but says NBF will have no comment on details until a closing. Efforts to contact KBS officials by press deadline were unsuccessful.