Rockwell Collins Inc, a supplier of avionics and other electronic systems for commercial and military aircraft, has agreed to buy aerospace communications firm Arinc Inc for $1.39 billion from the Carlyle Group LP . The transaction will combine Arinc's networks and services with Rockwell's avionics and cabin technologies to benefit from the growing field of aviation information management, Rockwell said in a statement on Sunday. Annapolis, Maryland-based Arinc is expected to report more than $600 million in revenue this year, Rockwell said. Carlyle bought Arinc in 2007 from a group of U.S. airlines for an undisclosed sum. They employee about 900 people in Anne Arundel County.