MANILA, NOV. 19 -- Philippine Foreign Secretary Raul Manglapus said today that Americans should not feel that their interests in the Philippines are threatened because of last month's killing of three U.S. servicemen outside Clark Air Base and the recent warning from communist leaders that American citizens living here had now become "targets for attack."

"Americans are exposed in this way all over the world" because of the U.S. military presence, Manglapus said in an interview. "Some resentment cannot be denied all over the world. Yet wherever they {terrorist killings} occur, American business is able to continue. American investors are able to prosper in places where Americans have been attacked."

He added, "We have not reached a point here -- and I don't think we ever will -- where nonmilitary Americans become targets." The three killed at Clark included two active duty servicemen and a U.S. Air Force retiree.

"They were innocent, but they were military," Manglapus said. "Obviously, the left wanted to send a message by killing them. Obviously, they delivered it."

{Meanwhile, police filed murder charges against 19 suspected communist rebels in connection with the Oct. 28 killings of the U.S. servicemen, United Press International reported from Angeles, where Clark Air Base is located. Only one of the suspects is in custody.

{A criminal complaint said the three Americans and a Filipino who tried to help one of them were gunned down in three coordinated attacks carried out within 10 minutes, several hundred yards from Clark's main gate.}

In the interview, Manglapus also said the Philippines plans to host an international conference next year of all countries that are in transition from authoritarian rule to democracy as part of a new effort to "broaden" Manila's foreign policy horizons beyond its traditional "special relationship" with the United States.

Manglapus said President Corazon Aquino officially approved the plan as a new policy today.

He said the invited countries would include Greece, Spain, Portugal, Argentina, Brazil, Honduras, the Dominican Republic and possibly Haiti, which this month is scheduled to hold its first free elections since deposed president Jean-Claude Duvalier fled into exile in February 1986.

The goal of the conference, he said, would be to "reinforce each other {and} to share impressions" on common problems.

"What's happening in the Philippines is what has happened to every country that has returned to democracy in the last 14 years -- a period of instability" and coup attempts, he said.

Manglapus said he hopes the Manila conference will give the Philippines the same kind of international status and global forum that Indonesia achieved under the late president Sukarno by hosting the first Bandung conference for nonaligned countries in the 1950s.

While stressing the need for more independence in foreign relations, however, Manglapus said the Philippines is not seeking to shift its policy away from the United States. Its goal, he said, is only to "widen" its foreign policy horizons to recognize that the Philippines also has close historical links to Asia, since Filipinos are of Malay stock, and Western Europe, because of the long period of Spanish colonization.