CHICAGO — Avison Young has brokered the sale of Kennelly Square in Chicago’s Old Town neighborhood for $78 million. The buyer, Strategic Properties of North America, plans to convert the 268-unit condominium building into rental apartment units. James Hanson, Richard Hanson and Paul Cohen of Avison Young represented the seller, Kennelly Square Condominium Association. More than 75 percent of the owners at Kennelly Square voted to approve the sale, a threshold required by the Illinois Condominium Property Act. This strategy reflects a growing trend in Chicago’s multifamily market as investors and developers identify opportunities to meet strong demand for rental units, according to Avison Young.