Ross Perot Jr.’s Hillwood Investments said Monday that it has sold part ownership in more than 8 million square feet of industrial buildings in Dallas and elsewhere to ING Clarion Partners, a real estate investment firm based in New York. Terms of the transaction weren’t disclosed, but the new partners say they are going to do other warehouse property transactions together. “It made sense that we could continue to grow and grow with great partners that understand real estate,” said Todd Platt, chief executive of Hillwood Investments.ING Clarion Partners’ Lion Industrial Trust, which did the deal with Hillwood, is already one of the country’s largest industrial investors. In 2002, Lion Industrial Trust bought Dallas-based Crow Holdings Industrial Trust in a deal valued at more than $1.5 billion.The sale of part interest in the 16 Hillwood buildings allows the company “to strategically access the capital” to use for other investments, Mr. Platt said.The Hillwood sale includes about 3 million to 4 million square feet of industrial buildings in North Texas plus properties in Memphis, Pennsylvania and Southern California, Mr. Platt said. None of Hillwood’s properties at the AllianceTexas project in Tarrant and Denton counties was included in the deal, he said. The AllianceTexas properties represent about half of Hillwood’s industrial holdings, Mr. Platt said.Hillwood will continue to operate and lease the properties it now owns in partnership with ING Clarion.Plus, Mr. Platt said, the two firms will jointly look at additional development. “Hillwood outside of Alliance has enough land to build 26 million square feet of industrial around the country,” he said. “This gives us a platform that we can access markets we are not in.” The partnership should also make it easier for Hillwood to tap additional capital, Mr. Platt said.”They are precisely the kind of partner that ING Clarion seeks for a long-term relationship,” John Thomas, chief operating officer of Lion Industrial Trust, said in an announcement.ING Clarion manages more than $10 billion in real estate investments on behalf of private clients.The joint venture deal is similar to Crescent Real Estate’s recent sale of part interest in some of its landmark properties. Hillwood is one of the country’s top five industrial builders and one of the most active in North Texas.