Robin Swanger, AspenTech's marketing director, tells GlobeSt.com that a medium-term lease has been signed for four full floors--4, 14, 15, and 16--in a 25-story, 574,000-sf office building owned by Chicago-based Equity Office Property Trust. She says the relocation will be done by the deadline.

The Cambridge, MA-based AspenTech has relinquished a master lease for a five-year-old build-to-suit, the 250,000-sf Eldridge Green at 1293 Eldridge Parkway in the Energy Corridor. Nine days ago, Citgo Petroleum Corp. announced a plan to take over Eldridge Green in a corporate headquarters relocation from Tulsa, OK.

Swanger says AspenTech's been trying to shed excess space most of this year due to an expansion of an overseas network that now provides 60% of the firm's annual revenue. She says 2500 Citywest won the nod because it's a stone's throw from the Westheimer Road exit of the Sam Houston Tollway, a direct connect to the George Bush International Airport. She says the decision also was sealed by floor layouts allowing a clustering of office space for geographically-assigned groups.

Equity Office has a going rate of $19 per sf attached to the 22-year-old building, positioned in a submarket favored by high-tech companies. Equity Office used an in-house broker to negotiate the terms while Michael Ippolito of Newmark New Spectrum in New York City brokered for AspenTech.