American Construction Source, created in September by Santa Monica-based private equity firms Clearlake Capital Group and Angeles Equity Partners, bought its fourth building materials supplier in less than two months. American Construction Source said Nov. 14 that it had acquired Stillwater, Minn.-based Arrow Building Center. Financial terms of the transaction were not disclosed. In recent months, American Construction Source, which has a goal of creating a leading national building products distributor, has bought Meeks Lumber Co. in Springfield, Mo., and Edwards Building Center and Breckenridge Building Center, both based in Colorado. Edwards and Breckenridge provide services, and lumber and building materials in key urban markets in Colorado. The Arrow Building Center serves customers in Minnesota and Wisconsin.