CARLSBAD, CALIF. — Newport National Corp. is developing the third and final building at its Ventana Real Office Park in Carlsbad. The last building, located at 2175 Salk Ave., is slated for completion in October. The Class A office park will feature three buildings totaling 218,530 square feet. Currently signed tenants include Euro RSCG Direct Response, BBQ’s Galore, EISI and Brightstar. McArdle Associates Architecture is providing architectural services for the project. TSA Contracting Inc. is serving as general contractor. The property is being marketed by Mark Avilla, Justin Halenza and Matty Sundberg of Grubb & Ellis|BRE Commercial.