U.S. military officials in Panama are certain Gen. Manuel Antonio Noriega will manipulate the country's national election Sunday.

Noriega has ruled Panama from his Cabinet post as defense chief since he orchestrated the ouster of President Eric Arturo Delvalle in February 1988. The candidate he backs for president in the election, Carlos Duque, is considered a puppet to the Noriega military regime.

U.S. officials believe Noriega and his military officers run a corrupt military dictatorship that is involved in trafficking drugs to the United States, making his regime a threat to U.S. national security. Some 50,000 Americans live in Panama, including 10,000 military personnel.

Efforts by the United States to squeeze Noriega out of power through economic sanctions have failed,. A coalition opposing Noriega isn't given a remote chance of winning the Sunday election fair and square because of Noriega's military strength, even though several polls show Noriega's support at only about 25 percent.

Several top U.S. military officials assessed Panama's pre-election turbulence for an official party accompanying Utah Gov. Norm Bangerter to Central America. Four-star Gen. Fred F. Woerner, commander in chief of the U.S. Southern Command; Maj. Gen. Bernard Loeffke, U.S. Army South Commander and United States Army Security Assistance Agency for Latin America; and other top military aides gave the briefing in Panama at the United States' military headquarters for Central and South America.

Protecting the Panama Canal is key to the U.S. military mission in Panama. The United States has agreed, by treaty, to turn control of the canal and the adjacent military installations over to Panama in 2000. The United States would be much more comfortable turning the canal over to a democratic government, rather than an unstable Panamanian government.

Woerner said the Southern Command also operates its counterdrug assault from Panama and uses the headquarters to verify the Central America Peace Plan and promote democracy in the region.

The military officials requested information from the briefing not be attributed to individuals because, they said, it would only worsen diplomatic relations with Panama, which took a nose dive when Noriega was indicted on a federal drug trafficking case in Miami in February 1988.

From the U.S. military mind-set, the smartest thing Noriega could do is use his military underlings and his power to arrange for his opposition to win the election in a way that he retains his Cabinet post.

That arrangement would create a diplomatic dilemma. The United States would have to deal with Noriega to maintain diplomatic ties with Panama after indicting him on drug charges and after supporting a coalition of opposition forces.

The plausibility of that scenario, however, is waning because it would be risky for Noriega to help seat an opposition candidate.

US News & World Report reported last month that President Bush won approval from congressional intelligence committees for the CIA to provide more than $10 million in aid to Noriega's political opponents. The U.S. military officials in Panama said they know no more about the money than what they read in media reports.

American military officers stationed in Panama said green and white political posters from the opposition candidates surface regularly on walls and sign posts, but within 24 hours they are plastered over with the red, white and blue posters of the Noriega-backed candidate.

The U.S. officials are confident Noriega, although unpopular in the polls, has enough power to commandeer the election in his favor. Noriega could postpone the election or cancel it outright if conditions don't seem ideal for him, one of the U.S. officials said. "I lean toward a gross rip-off rather than a cancellation of the election."

The U.S. military officials concede the economic sanctions enforced against Panama as an attempt to squeeze Noriega out have failed. But they say the only other option for the United States is to up the economic ante somehow to force him out and restore democracy to Panama.