Federal City Council President Sol M. Linowitz says he believes the federal government could develop a policy of more "justice" for the District of Columbia by considering a regional approach to the city's problems.

Instead of having a special adviser in the White House devoting most attention to D.C. affairs - a position occupied in the Carter administration by Martha M. (Bunny) Mitchell - Linowitz would prefer a full-time Office of National Capital Area affairs.

He reasons that an abstract concept known as the "federal interest" in D.C. has not been served well in recent years - by a congressional impasse over a budget for the city government brought about by the city's plans for a convention center, by requiring four separate federal reviews of the D.C. budget, or by the notion that Washington is "just another city so far as the federal government is concerned."

"It stains one's imagination to conceive of a federal interest in [the convention center] which could have justified denying the city a budget for one half of its fiscal year," said Linowitz last week in remarks to a luncheon of his organization, a group of top business and civic leaders here.

In searching for a definition of what should be the federal role in Washington, Linowitz found three "realities" he said he thinks should guide planners:

Constitutional, creating a role which should be limited to "positive or constructive oversight . . . to enrich and enhance the nation's capital, to add to what is already being done by the District government."

. Economic, forcing "special obligations" on the federal government because it is the dominant economic force in the region, "just as a private company would be expected to assume major resposibility in an area it was the dominant employer and economic force."

. Goegraphic, providing the White House an opportunity to carry out its urban policy, aimed at more agressive actions by the states to solve metropolitan area problems.

Washington's economy is interdepent, interstate and carries a heavy federal involvement, making it unique in the country.

To meet such a challenge, Linowitz says he thinks the White House should assume a local leadership role. By broading the scope D.C. liaison Mitchell to the entire metropolitan area, " the office I am proposing would work closely in support of initiatives by the various local jurisdictions and by the Council of Governments for regional betterment," Linowitz said.

He also called on President Carter to convene a "group of the finest and most creative minds from around the nation" to consider the future of Washington. And each Cabinet member should appoint a key to a new interagency task force that could coordinate federal initiatives in coordinate federal initiatives in the D.C. area, Linowitz suggested.