The Reagan administration is using stalling tactics to keep Congress from strengthening its oversight of covert intelligence operations round the world, the vice chairman of the Senate Select Committee on Intelligence charged yesterday.

Sen. William S. Cohen (R-Maine) said the administration is dragging its feet in arranging for top officials to testify on legislation that would require the president to notify lawmakers within 48 hours of any covert action, an idea that grew out of the Iran-contra scandal.

"It is clear that the administration opposes the requirement of 48 hours and is seeking to delay Congress from acting for as long as possible, anticipating that this bill will lose momentum in the press of other business" next year, Cohen said at a hearing.

"Should it pass, there will undoubtedly be a veto waiting for it. In any case, the delaying tactic is obvious even if covert. And I hope we will not acquiesce in its execution," he said.

The Senate panel and its House counterpart are expected to take action early next year on legislative packages to impose the 48-hour notice requirement along with other safeguards on covert activity.

Cohen and committee Chairman David L. Boren (D-Okla.) hope as well to write into law requirements that the president authorize any covert action in writing in advance and notify the intelligence committees of precisely who will be carrying it out.

Also under consideration is legislation by Sen. Arlen Specter (R-Pa.) that would create an independent inspector general at the Central Intelligence Agency and impose a mandatory prison term on government officials convicted of lying to Congress.