CIA Director William H. Webster repeated his opposition yesterday to placing an independent watchdog, similar to those at 19 other federal departments and agencies, in the Central Intelligence Agency.

Webster said a proposal by Sen. Arlen Specter (R-Pa.) to place an independent inspector general at the CIA "will actually prove to be counterproductive to an effective inspection and investigation process."

He told the Senate Select Committee on Intelligence that the presence of an investigator with access to personnel and secret records could deter foreign intelligence services and other sensitive sources from sharing information with the CIA, fearing its possible disclosure.

The proposal for an independent inspector general at the CIA grew out of last summer's Iran-contra investigation, which found the agency's current inspector general "lacked the manpower, resources and tenacity" to uncover many of the abuses turned up during that probe.

The current inspector general is chosen by the agency's director and lacks the institutional independence of the same post at most other federal agencies. The post is held by William Donnelly, a 33-year CIA veteran appointed by Webster.

Specter, a member of the Intelligence Committee, said the panel is unable to oversee the agency as thoroughly as an in-house watchdog would. He noted that other departments with sensitive intelligence operations, such as the Defense and the State departments, have independent investigators inside their bureaucracies.

Specter's bill would permit the CIA director to deny investigators access to documents or personnel if necessary to protect sensitive secrets or an active covert operation. But the director would have to defend such an action to the congressional intelligence committees.