The Reagan administration said yesterday it is postponing the imposition of $105 million in retaliatory sanctions on Brazilian exports, citing a new Brazilian law that could ease restrictions on U.S. computer sales there.

The sanctions had been intended in retaliation for Brazil's tight trade barriers against such imports, particularly against computer software.

But in a statement, U.S. Trade Representative Clayton Yeutter cited "recent progress" on the dispute.

"The United States will delay sanctions against Brazil pending review of the implementing regulations for Brazil's new software law," the statement said.

"Subsequent to that, we will review our options and consider what actions, if any, to take."

The administration had announced in January that it would impose the sanctions. However, the list of specific Brazilian exports to be targeted had never been released, even though a preliminary list included Brazilian-made shoes, aircraft, automobiles and electronics equipment.

The issue of access of U.S. computer software companies to markets in Brazil "will remain a high priority for the U.S. government," Yeutter said.

"Recent Brazilian actions, and discussions with representatives of the government of Brazil, demonstrate progress on this issue," Yeutter said. "Some of our immediate concerns have now been met."

The new Brazilian law will regulate commercial sales of all software, both domestic and foreign. It calls for new regulations to be issued by April 19.

"As a result, we feel it would be inappropriate and counterproductive to proceed without our previously announced plans to retaliate," Yeutter said.