For the second time in 10 weeks, black truckers halted construction all day yesterday at the site of the Washington Convention Center. The dispute was resolved later in the day, and work was to resume today.

The protest involved black drivers' demands for a new contract, and their allegations of unfair labor practices that exclude minorities from the job.

About 25 independent black drivers, informally respresented by the Metropolitan Truckers' Association, rolled into the Convention Center work site at Ninth and H streets NW at 6:30 a.m. yesterday.

They refused to move their turcks after the contractor, Lee Washington, who is black, had ordered crane operators to load trucks belonging to the Truck Brokerage Corp. instead of the MTA trucks.

The 30 drivers of the Truck Brokerage Corp. dozed and chatted in their stalled rigs, unable to work because the trucks belonging to the other drivers blocked the narrow H Street entryway to the site.

Fred Bradley, spokesman for the Metropolitan Truckers' Association, said that two weeks ago Washington ordered his drivers to use a dumping site in Beltsville, a requirement that added 30 minutes to the time needed to haul and dump a load there, and then return to the site.

The move cost the independent drivers who are paid by the load -- an estimated two to four loads a day. Bradley said that Washington failed to honor a commitment to pay his drivers compensation for the cost of the additional distance.

Washington denied this, and said the other drivers were called in after MTA workers frequently had fallen behind schedule.

The dispute was resolved by 5:30 p.m., Bradley said, after MTA drivers agreed to continue working under contract with the Truck Brokerage Corp.