A federal appeals court has ordered a fourth attempt at mediation in a long-running dispute over the state of Maryland’s treatment of its historically black colleges.

The black colleges say the state has underfunded them while developing programs at traditionally white schools that directly compete with them and drain prospective students away.

In 2013, a judge found that the state had maintained an unconstitutional “dual and segregated education system.” The judge said the state allowed traditionally white schools to replicate programs at historically black institutions, thereby undermining the success of the black schools.

Despite three previous tries at mediation, the two sides have been unable to agree on a solution.

On Wednesday, a three-judge panel of the 4th U.S. Circuit Court of Appeals ordered Maryland’s higher education commission and the coalition to begin mediation again to try to settle the 12-year-old lawsuit.