Deltek, a software provider backed by Thoma Bravo private equity, has acquired the Union Square software firm to build out its offerings for architecture, engineering and construction clients. Deltek, based in Herndon, Virginia, has more than 12,000 client firms in the architecture, engineering and construction space, while Union Square in Nottingham, England, has more than 450 firms in the industry in 15 countries as clients.

Deltek provides software for enterprise resource planning, or ERP, business development, project and portfolio management, and human resources management, with 22,000 organizations in more than 80 countries as clients overall. Besides its architecture, engineering and construction customers, Deltek targets clients in the accounting; aerospace and defense; energy, oil and natural gas; engineering procurement construction; government contracting; health care; management and IT consulting; legal; marketing; nonprofit; and research and development spaces. Union Square targets architecture, engineering and construction firms, providing project information and collaboration software featuring a central repository where all project information, including emails, drawing and other documents, can be stored.

PE firm Thoma Bravo, based in Chicago and San Francisco, has focused on investments application software, infrastructure software and technology-enabled services sectors, managing funds with more than $17 billion of investor equity commitments. Its list of recent acquisitions have included Imprivata (NYSE: IMPR), a health care IT security company; Bomgar, which provides secure access software for computer systems and devices, from TA Associates; Elemica, which provides supply chain operating network management software; and enterprise software firm Qlik Technologies Inc. (Nasdaq: QLIK).