Wallace Browne of the DUP, a former biology teacher, was last night elected lord mayor of Belfast with the cross-community support of the SDLP.
The DUP in turn helped elect SDLP councillor Pat Convery as deputy lord mayor.
Belfast councillors said this was the first time that the DUP and SDLP co-operated to elect their party members to the two top posts on Belfast City Council. The two posts were filled with the agreement of the Alliance Party, which holds the balance of power on the council. The outgoing lord mayor was Tom Ekin of the Alliance Party.
Mr Browne, who has been a councillor for the past 20 years, and a full-time councillor for the past five years, in DUP terms is said to be on the "progressive wing" of the party. Colleagues from opposing parties have described him as "quiet, unassuming and a gentleman".
In his acceptance speech, he said: "We must tackle the scourge of racism that still plagues our city and province. We believe all men and women are equal, and that must be evident through all our actions rather than simply words."