HOUSTON — HFF has arranged the sale of Houston Center, a 4.2 million-square-foot mixed-use property located near Toyota Center and Minute Maid Park in downtown Houston. The four-building property consists of three high-rise office towers and one 16-story office building situated atop of 196,000 square feet of retail space. The asset spans 9.2 acres and was 72 percent leased at the time of sale. Houston Center offers tenants several casual and fine-dining restaurants, a fitness club and a healthcare facility. Jeff Hollinden, Scott Galloway, Mark Gibson and Trent Agnew of HFF represented the seller, a group of institutional investors advised by J.P. Morgan Asset Management, in the transaction. The buyer was not disclosed.