Cuban President Fidel Castro has agreed to let 348 current and former political prisoners, all jailed at least 10 years, emigrate to the United States, the U.S. Catholic Conference said yesterday.

The Rev. Nicholas DiMarzio, executive director of the Roman Catholic agency's migration and refugee services, won the commitment from Castro during a meeting in Cuba last week, church officials said.

Castro agreed to issue exit permits for 204 persons on an updated U.S. Catholic Conference list of political prisoners, officials said.

DiMarzio said Castro told him an additional 144 persons still in prison and not on the agency's list will be given permission to leave Cuba. Last September, the Catholic conference and Cuban officials negotiated the resettlement of a group of 111 political prisoners and their immediate families.

The prisoners, former prisoners and immediate family members to be released likely will be transported to the United States in small groups and the first group probably will not arrive much before Labor Day, officials said.

Church officials said the Catholic agency and the Justice and State departments have begun consultations on processing the prisoners. DiMarzio said the political prisoners will be reviewed case by case to ensure they meet U.S. immigration requirements.

The U.S. Catholic Conference's effort to aid in the freeing of Cuban political prisoners is a result of a January 1985 meeting when a visiting delegation of U.S. bishops presented names of political prisoners to Castro and offered to assist in their relocation in the United States.