Reston-based DynCorp said yesterday that it will buy GTE Information Systems LLC, a subsidiary of GTE Corp., for an undisclosed amount.

GTE Information Systems, whose 1999 revenue is projected to be $235 million, employs 960 people at its Chantilly headquarters. The acquisition, which is expected to close by the end of the year, would increase DynCorp's annual sales to about $1.7 billion.

GTE Information Systems provides telephone and information technology services to government agencies and select commercial markets. GTE officials said the company agreed to sell the unit to DynCorp as part of an effort to shed non-core assets.

DynCorp officials said the acquisition would expand the company's information technology capabilities and give DynCorp access to new markets.

"The acquisition . . . is consistent with DynCorp's strategy of focusing on information technology and outsourcing solutions," DynCorp chief executive Paul Lombardi said in a statement released yesterday. "It brings DynCorp a level of technology expertise, particularly in the telecommunications and networking systems disciplines, that strengthens and expands the reach and the content of our current information technology practice."

He added that GTE's wireless technology business for state and local law enforcement agencies also complements DynCorp's technology offerings in the state market.

DynCorp, an information technology and outsourcing company that does business primarily with federal agencies, employs more than 16,000 technology and technical professionals who work at more than 550 company and customer locations around the world.

DynCorp--employee-owned and one of the largest private technology companies in the United States--has been considered a good candidate to go public, though the company says it has no current plans to do so.

That hasn't stopped DynCorp from growing, however. Last year, it bought FMAS, a Rockville-based medical data systems company. At the time, FMAS had annual revenue of $17 million and more than 300 employees.

Lombardi said acquisition of the GTE unit was part of a strategic plan set in motion in 1997 to find companies in the federal arena that complement DynCorp's information technology offerings. "And in this day and age of consolidation, there's not a lot of big ones left," he said.

CAPTION: The GTE Information Systems acquisition "is consistent with DynCorp's strategy of focusing on information technology and outsourcing solutions," chief executive Paul Lombardi said.