Catlyn Capital Corp. and Irving-based TDI Real Estate Holdings have closed on a $500 million joint venture platform to develop properties in the states of Texas, Arizona and Colorado. Recently, the two companies closed on a $50 million, 44-unit apartment development in Allen, Texas and a $65 million, 388-unit development in Scottsdale. The venture is finalizing construction plans on four additional communities, totaling 1,323 multifamily units, with a total cost of $185 million in the Phoenix, Dallas and Austin metro areas. In addition to the joint venture, TDI currently has 800 units under construction valued at $200 million. TDI is a real estate investment firm specializing in investing in multifamily assets. The company manages a portfolio of $1 billion in assets throughout the U.S. Catlyn Capital is based in Dallas, and was formed in 1991 as a vehicle for opportunistic investments in real estate.