Rep. Bruce A. Morrison (D-Conn.) said yesterday that the U.S. should oppose international bank loans to Chile because of human rights violations by the military government of Gen. Augusto Pinochet.

Morrison, who serves on a subcommittee that oversees loans by the World Bank and Inter-American Development Bank, told a news conference here that U.S. law prohibits approval of loans to governments engaging in patterns of gross violations of human rights.

Morrison, who took a fact-finding tour to Chile in April, released a report concluding that U.S. tax dollars are supporting a repressive dictatorship in Chile through the multilateral development banks. The report was the work of a human-rights advocacy group, Washington Office on Latin America, which sponsored the tour.

The report said U.S. efforts to block such loans would send a clear signal to the Pinochet government that the United States comes down firmly on the side of human rights and democracy in that country.

Morrison pointed out that Chile had the highest per capita debt in Latin America. The report estimates Chile's foreign debt at $20 billion.

Morrison said that the blockage of multilateral development banking loans would lead the way to democracy in Chile. He said the military there would think twice about supporting Pinochet if it sees already desperate economic circumstances worsening with a lack of an infusion of foreign capital to help service their debt.

The report said that the Reagan administration has supported almost every international development bank loan Chile has requested. "In 1981, Chile received more from the multilateral development banks than it had borrowed during the entire Carter presidency," it said. The United States approved $1 billion in loans for Chile last year. The total of multilateral development banking loans awaiting approval is $851 million, according to Washington Office figures.

Some members in Congress have asked the administration to take economic sanctions against Chile since the burning death of U.S. resident Rodrigo Rojas de Negri in Santiago on July 6. Congressional subcommittee hearings on the issue are scheduled today. Among the witnesses is Elliott Abrams, assistant secretary of state for inter-American affairs.