The negotiated lease term and rental rate were not disclosed by the parties involved. The full-service asking rate for space in the building is $27 per sf per year.

"Milliman loves the location of their offices in the downtown core, and this allows them to avoid the expense and disruption a move of that size would incur," says Milliman's broker, Rod Keefe of GVA Kidder Mathews. "They are very happy we were able to make a deal that allows them to stay."

Milliman currently occupies space on floors 36 to 39 and has temporary space on floors 30 and 34. When it grows to 90,000 sf during the life of the lease, it will consolidate employees now on floors 30 and 34 onto the 35th floor.

There is about 100,000 sf in the building being marketed for sublease, according to officespace.com. It was not immediately clear whether Milliman's space was included in that total. A representative of Unico could not be reached Wednesday for comment.