L-3 Communications Holdings Inc., the New York-based provider of translators to the U.S. Army, has agreed to buy a unit that makes night-vision equipment from Northrop Grumman Corp. for $175 million.

Northrop's Electro-Optical Systems business generated about $190 million in sales last year, L-3 and Northrop said this past week in separate statements. The Garland, Texas-based unit employs 1,000 people and makes sensors, weapons-sighting devices, laser-based equipment and night-vision goggles.

"There is strong demand worldwide for image-enhancing products," James Dunn, president of L-3's Sensors and Simulation Group, said in his company's statement.

Acquiring the business from Los Angeles-based Northrop means L-3's electro-optical and infrared unit will generate about $800 million in annual sales "with growth exceeding 10 percent," Dunn said in the statement. The transaction should be completed this quarter, the companies said.