Charlton Heston ("Ben Hur"), Charles Bronson ("Death Wish") and Charlie Sheen ("Platoon") made film debuts at the State Department yesterday as stars of a worldwide advertising campaign offering rewards of up to $4 million for information on major terrorist operations.

Secretary of State James A. Baker III said the actors, present only on videotape, would help spread the message that the United States can now offer twice as much as before "for information that prevents or resolves an act of terrorism or brings terrorists to justice."

The commercials, separately featuring the three stars and in six languages, will be played here and abroad to encourage viewers with any information about an act of terrorism to "be a hero" and contact authorities in their country, the nearest U.S. Embassy, or a post office box in the District. Confidentiality and protection are promised for those who speak up.

The rewards program started in 1984 with a maximum reward of $500,000, but Congress upped the ante to $2 million last year following the midair explosion of Pan Am Flight 103 over Lockerbie, Scotland.

Under the new program announced by Baker yesterday, the $2 million in federal money will be matched by donations of $1 million each from the Air Transport Association, representing the airline industry, and the Air Line Pilots Association, representing commercial pilots. Their contributions will be set aside for information about terrorist attacks on U.S. civil aviation.

Baker said at a news conference that the program was already "working effectively." But no rewards were made until the past year when slightly more than $500,000 was paid out. The biggest rewards, Baker said, went to informants who "facilitated the successful prosecution of an international terrorist."

Officials refused to identify the case, but it was apparently that of Fawaz Yunis, a former member of the Amal militia sentenced to 30 years in prison here last October for the 1985 hijacking in Beirut of a Royal Jordanian airliner with 70 passengers, including two Americans, aboard.

The FBI captured him in 1987 aboard a sailing yacht off the coast of Cyprus after a Lebanese informant lured him there with the promise of a drug deal.

Announcement of the worldwide "Heroes" campaign, with the commercials and glossy posters available in six languages, coincides with U.S. concerns over the possibility of Iraqi-sponsored terrorism around the world. A number of international terrorist organizations have established "presences" in Baghdad in recent weeks following Iraq's Aug. 2 invasion of Kuwait.

Citing "the threats that have come from Baghdad to utilize terrorist actions and activities to further Saddam Hussein's interests," Baker said "we take those statements very seriously and we are quite concerned about them."

Terrorist attacks "are all meant to seize us with horror, to bring daily life to a standstill," Baker said.

The State Department coordinator for counterterrorism, Morris Busby, said the "Heroes" campaign has been "in the works" for seven or eight months and was not related to the Persian Gulf crisis. He said he hopes to see the public service commercials on at least one American network soon. U.S. embassies overseas have been asked to help with placements abroad. The TV spots and radio versions were produced in English, Arabic, Spanish, German, French and Greek.

And how were the actors picked? Bronson has played a hitman, not to mention "Machine Gun Kelly," while Sheen has had a role dispatching Arab terrorists and Heston has played everyone from Moses to Marc Antony.

"They were interested in doing it and they offered their own time," Busby said.

"If you have any information about an act of terrorism, you can be a hero by saving innocent lives. . . .

"Now, the U.S. government, along with the pilots, and airlines are offering up to $4 million for this information.

"Are you the next hero? Please contact the authorities or the U.S. Embassy."