Rockville Mayor William E. Hanna Jr. was reelected to a third consecutive two-year term of office this week and the Independents for Rockville (IFR) retained control of the four-member City Council.

However, Kenneth F. Sullivan of the Alliance of Rockville Citizens (ARC), which was offering its first slate of candidates, won one of the council seats, all of which had previously been held by the IFR.

Hanna defeated ARC mayoral candidate George Northway by 2,052 votes to 1,611, according to the city election clerk.

Incumbent council members Phyllis B. Fordham and John R. Freeland, both endorsed by the IFR, won reelection. A third member of the IFR slate to win a council seat was John G. Tyner II.

Two members of the outgoing council did not seek reelection. They are Richard R. Haight and Robert E. Buchanan.

Fordham received d2,122 votes; Freeland, 1,990; Tyner, 1,756, and Sullivan, 1,775.

Of the unsuccessful council candidates, Gerald R. Cichy of the ARC slate received the greatest number of votes - 1,738.

A total of 3,688 people out of Rockville's 10,439 registered voters cast ballots.

Mayor B. Daniel Walder and Councilman Bruce A. Goldensohn will oppose each other May 8 in the Gaithersburg election for mayor.

Walder and Goldensohn defeated Ray Goddard in the April 17 primary. Of Gaithersburg's 10,478 registered voters, 850 turned out for the primary. Goldensohn received 502 votes; Waldes received 242 votes; and Goddard received 84 votes.

Goldensohn, 35, of 210 Goldkettle La., is a research specialist for the Defense Intelligence Agency at the Pentagon. He has been a Gaithersburg councilman for two years and was a member of the Gaithersburg Planning Commission from 1972 until 1976. He was chairman of the planning commission from 1975 until 1976.

Goldensohn is married and has a six-year-old daughter.

Walder, 45, of 424 E. Diamond Ave., has served as mayor of Gaithersburg for two years. He is an architect and has been employed by Montgomery County as a Capital Projects coordiantor and is a member of various civic associations.

Walder is married and has two daughters and a son.