Defense Secretary Frank Carlucci described America's scandal-ridden weapons procurement system Saturday as unwieldy and open to manipulation, only weeks after his spokesman defended Pentagon purchasing practices.

In a speech to the Philadelphia World Affairs Council, Carlucci said decisions involved in the complex process of developing and building high-tech weapons leaves the system open to congressional interference and political influence."The procurement process has become exceedingly cumbersome and complex - characterized by multiple decision points, each of which provides opportunities for congressional micro-management and influence by special advocates," Carlucci said. "As a result, the process creates incentives that reward precisely what we want to avoid."

Carlucci's remarks appeared to contrast sharply with those made by his spokesman, Dan Howard, two days after FBI and Naval Investigative Service agents last month raided the offices of Pentagon officials, defense contractors and consultants suspected in the scandal.

At that time, Howard said, "The secretary is confident that we have a very solid, adequate acquisitions process . . . we feel the overall mechanism is sound."

But Carlucci told the world affairs group that the system has driven defense contractors "to maximize short-term profits and seek advantage in the political arena.

"The best way for contractors to do that in our current system is to invest in `market intelligence' - a euphemism for hiring consultants and lobbyists to intervene in the process in the executive branch and on Capitol Hill," Carlucci said.

"We must reduce the number of opportunities that now exist for influencing procurement decisions, what might be termed points of vulnerability perhaps even venal vulnerability in certain areas," he said.

But, Carlucci added, a "straightjacket" of new procurement rules should not be added to the Pentagon's existing system.

In one of the latest revelations to come out of the scandal, a search warrant unsealed Friday said the FBI suspects Melvyn Paisley took payoffs or gifts from two giant defense contractors while an assistant Navy secretary.

Paisley, who left the Navy in 1987 to return to the private sector as a consultant, already has been identified as a central figure in the inquiry because he allegedly passed bribes to Pentagon procurement officials on behalf of the McDonnell Douglas Corp.