EVANSTON, ILL. — Investcorp has sold its ownership stake in Orrington Plaza, a 20-story office tower in downtown Evanston. The sales price was not disclosed. Golub & Co., which purchased the asset with Investcorp in 2013, will maintain an ownership stake in the building by co-investing with a new institutional capital partner and will continue to operate, manage and lease the property. Located at 1603 Orrington Ave., the property features 309,000 square feet of office space and 30,000 square feet of retail space. Next of Kinship restaurant and café as well as a full-service JP Morgan Chase branch occupy the retail portion. Paul Lundstedt and Dan Deuter of CBRE represented the sellers. The new capital partner is GEM Realty, according to local media reports.