The Seattle-based insurance giant's new space will be in the first phase of Shea Properties' $350-million Vantis development, which is rising on a 40-acre site near the intersection of Laguna Hills Drive and Enterprise. The class A project, inside the master-planned Aliso Viejo Town Center, will have more than 1.5 million sf of space when completed several years from now.

The pact is among the largest lease transactions of the year in Southern California, where activity has slowed in lock-step with the softening economy. The South County market has been particularly hard hit because it has a high concentration of tenants and owner-users involved in the struggling high-technology center.

Orange County-based Shea Properties was represented in the lease negotiations by a Colliers Seeley International Co. brokerage team of Tim Joyce, Kathy Morgan and Oliver Fleener. Safeco was represented by Dennis Richardson and Rick Kaplan of Cushman & Wakefield.