The D.C. Board of Labor Relations dismissed yesterday objections to the victory of the International Brotherhood of Police Officers in a representation election, paving the way for IBPO certification as D.C. police officers' bargaining agent.

The challenges were filed last year by the Police Association of the District of Columbia, which was outpolled by IBPO in the March 1978 election.

Officers of the losing side could not be reached last night and it was not clear if the labor relations board's ruling would end the long history of contention that surrounds the attempt to pick a bargaining agent.

Until 1974 the police had never had a formal bargaining agent, but the Police Association provided representation. In 1974, local 442 of IBPO won a representation election and became the bargaining agent for police officers through the rank of sergeant.

In May 1977 the D.C. Police Association defeated IBPO in another representation election, but IBPO filed a successful challenge and a new election was ordered.

IBPO was certified the winner of the most recent election, by 1,772 votes to 928, but the Police Association filed challenges that were the subject of yesterday's labor relations board announcement.

The labor board said its action would enable IBPO and the police department to begin negotiating a new labor-management agreement. Such talks were postponed pending the outcome of the dispute.