Military ship builder Huntington Ingalls Industries Inc. /zigman2/quotes/201887483/composite HII -1.72% announced Tuesday an agreement to buy Alion Science and Technology, a provider of services for the defense marketplace, for $1.65 billion in cash from Veritas Capital. Huntington Ingalls expects the deal, which is estimated to close in the second half of 2021, to be "significantly cash flow accretive" in fiscal 2022 and add to net earnings per share in 2023. "Today's announcement, coupled with our previous investments in leading edge technologies, such as cybersecurity and autonomous systems, reflects our commitment to stay on the cutting edge of critical, high-growth national security solutions and generate significant long-term value for our shareholders," said Huntington Ingalls Chief Executive Mike Petters. Shares of Huntington Ingalls, which had a market capitalization of $8.53 billion as of Friday's close, were still inactive in premarket trading. They have rallied 24.3% year to date, while the S&P 500 /zigman2/quotes/210599714/realtime SPX -2.27% has gained 15.9%.