The Norfolk Southern Corp. plans to close its Washington office, the former headquarters of the Southern Railway, and transfer most of its more than 500 employes to Norfolk, Atlanta or Roanoke.

Officials of the Norfolk Southern, a holding company created by the merger of the Southern and the Norfolk & Western railroads last summer, said yesterday that they could not say exactly how many workers would be shifted out of Washington, but sources said that "no more than a handful" would remain.

Employes in the Southern Building at 15th and K Streets NW were told of the decision in a letter from Norfolk Southern President H. H. Hall last Friday. Hall termed the decision to move "extremely difficult," and added that it was made "with the full realization of its impact on the lives of our loyal employes and their families."

"In general," he said, "the plan is to move those functions whose principal work is in support of Norfolk Southern to Norfolk or Roanoke, and those whose work primarily supports Southern Railway activities to Atlanta."

A spokesman for the company explained that since the merger, some Southern employes, particularly in finance and marketing, had been shifted to the holding company's payroll, though they had remained here. These workers would presumably be shifted to Norfolk or Roanoke, though the spokesman said plans are not complete.

Other employes, such as Southern President Edward B. Burwell, several vice presidents and their staffs, have continued with the Southern and appear ticketed for Atlanta. None could be reached for comment last night.

The spokesman said some public affairs and legal employes would remain in the District. "We plan to have a presence here," he said.

The fate of the Southern's building at 920 15th St. NW, headquarters of the line since 1928, remained unclear. Norfolk Southern spokesmen said they knew of no plans for it, though one company source said he was certain that the building had entered into the equation of the move. "I'm sure they figured what they could get from selling it or leasing it," he said.

Hall's letter said moving the railroad's offices out of Washington is "necessary for the continued well-being of our company."

Another company spokesman said that the primary goal is to "improve our efficiency . . . , reduce us from four key points to three."

He said no time frame has been set, but the company "hopes to carry out the move in an orderly fashion."

Norfolk Southern officials were reluctant to go beyond Hall's letter yesterday, but it was known that some employes have been told individually that they are staying. Among these is Virginia state Sen. Wiley F. Mitchell Jr. (R-Alexandria), of the company's legal department.