July 6 (Reuters) - Military shipbuilding firm Huntington Ingalls Industries said on Tuesday it would buy Alion Science and Technology for $1.65 billion in cash from Veritas Capital to boost its national security solutions portfolio.

Alion provides engineering and R&D services to the United States Department of Defense. (Reporting by Sanjana Shivdas in Bengaluru; Editing by Krishna Chandra Eluri)