The Federal Communications Commission is negotiating to move its downtown headquarters and 1,700 employes into a controversial Arlington high-rise office building -- in apparent iolation of both a presidential order and the FCC's charter, which requires that it be located in the District of Columbia.

The proposed move to one of the 30-story Twin Towers now being constructed in Rosslyn has been under negotiation for almost a year. During the same period, the U.S. Department of Justice and a sister federal agency, the Department of Interior, were suing to block construction of the skyscrapers.

The 30-story buildings, one to be completed next spring and the other in 1982, will be the tallest in the Washington area. They have been called "monsters" by Interior Secretary Cecil D. Andrus because they will loom like shadows behind the Lincoln Memorial and other downtown monuments.

Most of the FCC offices are now in a building at 1919 M St. N.W. The chairman of the National Capital Planning Commission, David Childs, said yesterday of the FCC's plans to move to Arlington: "It is appalling that a federal agency is planning to lease space in a building that so dramatically violates what was intended to be the natural setting for the nation's capital."

The FCC move is being made possible by a little-noticed rider in the 1981 budget, which permits the agency to by-pass normal federal leasing procedures and lease its own office space.

A spokesman for the General Services Administration, chartered in 1949 to be the sole procurer of federal civilian office space here, yesterday also criticized the FCC plans as a bad precedent.

If all 140 federal agencies here began scrambling to lease their own offices, there would be chaos, said James Whitlock, assistant administator for space management. Whitlock also questioned whether the FCC needs new offices in the first place and whether the Twin Towers move, "about which we've been told nothing," might not be extravagantly expensive.

No FCC officials could be reached yesterday to comment on the proposed move or the costs involved. Arlington Towers developer Stanley Westreich confirmed that the FCC has been negotiating over the office space for some time.

In a recently approved House ammendment to the 1981 appropriations bill the FCC is given permission to lease office space in the District. But the rider then defines the District "to include an area within two miles of the present District boundary," thus extending FCC's leasing privileges into most nearby Washington suburbs. This apparently will permit the FCC to ignore its own 1934 charter, which states the commission must meet and have its principal offices "in the District of Columbia."

"The Senate is scheduled to vote on the amendment later this week.

A move to Rosslyn appears to violate President Carter's 1978 executive order that all federal agencies locate or relocate in urban areas, a policy that was crucial to the recently approved move of the Nuclear Regulatory Commission to a new headquarters for its 2,600 employes in Silver Spring, considered a depressed urban area under federal guidelines.

While Washington has no clearly defined "urban area," federal officials doubt that glassy, high-rise Rosslyn meets the President's criteria of "a centralized community business area" in need of revitalization.

The District does. But then, at least according to House Bill 7584, Rosslyn is in the District.