Amtrak's chief operating officer has written Interior Secretary Cecil D. Andrus to ask that loiterers be removed from the National Visitor Center at Union Station.

The Interior Department rents the grand old building and has coverted most of it to the National Visitor Center, as Congress directed. But a deep cut in the center's budget has brought a drastic reduction in hours of operations, lowered light levels, less frequent custodial care and an increase in loitering, particularly at night.

The problem is that the National Visitor Center is still the front door to the city's only passenger railroad station, even though the closest railroad track is a full one-third of a mile from the front door. The real Union Station is now located in that small motel-lobby-like building out back.

"Unless steps are taken to control the activities of loiterers at the visitors center, our passengers and the visitors at the center will continue to be subject to solicitation and other forms of harassment, perhaps even assault, from these persons," Martin Garelick, executive vice president and chief operating officer of Amtrak wrote to Andrus.

"I urge you," Garelick said, to provide proper security and instruct personnel "to remove loiterers from the building."

A spokesman for Andrus said the secretary received the letter yesterday and that a reply would be formulated.

However, "there really isn't much we can do," he said.

George Berklacy, of the National Park Service here, which runs the visitor center, explained that D.C. has no vagrancy law and the visitor center is a public building. Therefore, if nothing illegal is happening, nobody can be removed.

The visitor center operating budget was reduced by Congress from a requested $3 million to $750.000 in anticipation of an agreement to reduce visitor center activities, turn the building over to the Department of Transportation and use it once again as a railroad station.

However, the funding necessary to do that and final plans got hung up in a House-Senate battle, and Congress adjourned without solving the problem.