Mayor Marion Barry announced yesterday that he had chosen Barbara Charlotte Washington a Capitol Hill lawyer and the sister of the chairman of the District's Democratic party, as the new chief lobbyist for city government.

The mayor also formally announced his nomination of Aida Berio, a national coordinator for field services at the U.S. Equal Employment Opportunity Commission, to be the new director of the D.C. Office of Latino Affairs.

Washington 37, will replace Judith W. Rogers as assistant city administrator for intergovernmental relations effective July 2. In April, Barry nominated Rogers to become D.C. Corporation Counsel.

Washington was born in Blakely, Ga., grew in in Newark and graduated from Rutgers Law School in 1973. Since 1977, she has been minority chief counsel and staff director for the House District Committee, Her brother is Robert B. Washington Jr., chairman of the D.C. Democratic State Committee and a major lobbyist of city government.

Berio, 50, was born in Corozal, Puerto Rico and graduated from Roosevelt High School in the District and Georgetown University. Berio's nomination, which must be confirmed by the City Counsil, was strongly supported by the D.C. Coalition for Women, of which she is a member. Berio will replace Carlos M. Rosario, who Barry declined to reappoint. CAPTION: Picture 1, BARBARA C. WASHINGTON . . . will replace Judigh W. Rogers; Picture 2, AIDA BERIO . . . will replace Carlos M. Rosario