Mayor Marion Barry made an unexpected visit to Mount Pleasant late Thursday night and successfully quelled -- at least for now -- the growing anger many of Washington's Hispanic leaders have expressed toward his administration.

As a result of "Barry's trip to the barrio," as it was dubbed instantly by the participants, a demonstration against the city government planned for yesterday afternoon was called off. Instead, at a press conference originally intended to announce the protest, Latino activists applauded the "very positive" outcome of the mayor's visit.

"We're not lowering our guard," said Enrique Rivera, director of the Latin American Youth Center, "but Barry did commit himself to a process of addressing the concerns we've brought before him."

Barry received considerable support from Hispanic leaders during his campaign but since he took office he has failed to appoint any Latinos to his personal staff. He has made promises, but has failed to act on them, many Latinos have complained.

Barry suddenly scheduled the meeting late Thursday, according to his aides, after it was clear that problems with funding for the youth center at 3045 15th St. NW through the federal Comprehensive Employment Training Act (CETA) had further inflamed Latino discontent with the local government.

At 9:30 p.m. Thursday, Barry and Jose Gutierrez, one of two Hispanics who are members of the city administrator's staff, conferred with three community leaders in the delapidated second-floor offices of the youth center. Barry stayed for more than an hour and Gutierrez until well after midnight, according to participants in the meeting. Several of the youths employed at the center were also present.

Rivera, as well as community activists Pedro Lujan and Harry Quintana who attended the Thursday night meeting, said yesterday that they understood that Barry's administration might still be suffering from problems such as funding for the youth center, left over by his predecessor Walter Washington.

The D.C. Department of Labor last September promised the youth center $70,000 for a job training program to begin in October. Neither a contract nor the money had come through by January.In February, after some youths had already been hired, Rivera said he was informed that the contract had "gotten lost somewhere."

The first check, finally was delivered Thursday afternoon, Rivera said.

In a statement at the press conference delivered for Barry by city administrator Elijah Rogers, the mayor called the loss of the program "inexcusable," and assured the Latinos that he would review the 39 resumes sent to him by the Council of Hispanic Agencies "for possible additions to my staff."

The audience outside the youth center, which included several representatives of national Hisanic organizations as well as the teen-agers employed there, burst into cheering and song.