Asgn Inc. has acquired an information technology and cloud computing company that serves the federal government. The Calabasas staffing company will pay $46 million for DHA Group Inc., a Washington, D.C. firm that supports the FBI and other federal agencies in the Justice Department, Commerce Department and Pentagon. DHA will become part of Asgn’s ECS Federal LLC business segment in Fairfax, Va. Chief Executive Peter Dameris said the acquisition was attractive in further deepening ECS’s long-term relationships with customers in homeland security, law enforcement, defense and intelligence agencies. “We intend to grow ECS to over $1 billion in revenues on or before 2021 through strong internal growth and targeted acquisitions, which meet specific profile requirements, complement our current service offerings and enhance our value proposition to our clients,” Dameris said in a statement. Shares in Asgn (ASGN) closed Monday down 40 cents, or less than 1 percent, to $61.76 on the New York Stock Exchange.