For William H. Borten, the 50-year-old president of Atlantic Research Corp., the transition to chief executive officer was a natural one.

Coleman Raphael, chairman of the board, last week announced he has relinquished the title of chief executive officer to Borten, his colleague of more than 14 years, in a move that came as no surprise and is not expected to mean any major change for the diversified-technology firm and government contractor.

"It is important that the company continue to grow, that the stock continue to go up and that the measures of success continue to be what they have been -- all without my continuing to play a major role. And that's where I think we are," Raphael said in an interview.

Raphael, 60, who owns more than 5 percent of the company's stock for a total investment of $9.9 million, will remain chairman of the board and will continue to be involved in the long-range planning of the firm.

Borten said of Raphael, "I will continue to use him as a sounding board."

Their relationship dates back to the 1960s when Borten was No. 2 to Raphael at the space and electronics systems division at Fairchild Industries Inc. Raphael signed on as president of ARC in 1970 and recruited Borten a year later when the company had $16 million in sales and was losing money.

The two of them designed a successful formula for turning the company around and have enjoyed substantial increases in revenue and profits for the past 10 years. This year, after completing the $24 million acquisition of Systematics General, another high-tech firm specializing in computer-communications security, the company is expected to report sales of about $230 million, analysts say. That would make Atlantic Research the 24th-largest publicly owned company in the Washington area.