* XO Communications completed its acquisition of Dallas-based Allegiance Telecom's assets for $322 million in cash and about 45.4 million shares of XO common stock. The acquisition of Allegiance, which filed for bankruptcy protection last year, significantly expands the Reston telecommunications company's local market coverage across the country. The two companies also settled a number of disputes, and the bankruptcy court is expected to approve that agreement soon, according to XO.

* Anteon International, a Fairfax government technology contractor, won a five-year contract worth up to $21.7 million from the U.S. Army Ordnance Mechanical Maintenance School at the Aberdeen Proving Ground in Maryland. Anteon will develop technical and professional development courses and provide instructors for a variety of materiel maintenance specialties.

* ObjectVideo named Stephen D. Vermillion vice president of government affairs. Vermillion will handle the Reston video surveillance software manufacturer's dealings with Congress, the White House, government agencies, Cabinet departments and international agencies. Before joining ObjectVideo, Vermillion served as chief of staff to Rep. Lincoln Diaz-Balart (R-Fla.).

* SafeNet, a Baltimore information security company, named Howard Seeger vice president for business development of corporate alliances. Seeger will lead executive level relationships with system integrators and telecommunication service providers. Seeger most recently served as vice president of system integrator alliances at Qwest Communications International.

* USEC, a Bethesda enriched uranium supplier, named James F. McDonnell to the new position of vice president and chief information and security officer. He will be responsible for the strategic direction of information technology programs as well as overall physical and data security. McDonnell most recently served as a director in the U.S. Department of Homeland Security's Office of Infrastructure Protection.

Compiled from reports by Washington Post staff writers, PR Newswire and Business Wire.