Michael Vernon Townley, a 35-year-old American who has lived most of his life in Chile, was ordered held without bond yesterday as a material witness in the September 1976 of former Chilean ambassador Orlando Letelier.

Letelier and an aide, Ronni Moffitt, were killed in Washington when a bomb exploded under the car they occupied as it traveled around Sheridan Circle NW. The FBI has been conducting an extensive investigation into the assassinations, and reportedly has concluded that the bombing was carried out by right-wing Cubans in American acting on behalf of Chile's secret police, known as DINA.

Townley is reported to have traveled to the U.S. under a false passport about a month before Letelier's murder and met with other persons in the U.S. at that time, according to investigators. These persons are suspects in the assassination plot, it was said.

As a material witness, Townley can be held for an unspecified time without bond. Neither Townley nor his attorney, Seymour Glanzer, objected to that procedure yesterday.

Assistant U.S. Attorney Eugene M. Propper, of the major crimes division, who has been directing the investigation with FBI special agent Carter Cornick, said the presentation of Townley to U.S. District Chief Judge William B. Bryant yesterday morning was required since Bryant had signed Townley's arrest warrant on the material witness charge.

Townley, reportedly a DINA agent, was expelled from Chile last week on charges that he violated registration laws by traveling to the country using flase documents. He was arrested by FBI agents on the plane trip from Chile to the U.S.

It is unknown whether Townley has expressed a willingness to cooperate with American authorities who are known to want him as a witness against persons in Chile who might have directed the assassinations.

However, persons familiar with the manner in which U.S. Attorney Earl J. Silbert's office conducts its lengthy that Townley would be granted total immunity but rather would be asked to plead guilty to a serious felony.

U.S. authorities are known to fear for the safety of Townley, who is being held under U.S. guard in Maryland. No criminal charges have been lodged against him, although investigators are believed to have enough information to lodge at least technical charges against him concerning the use of false passports.

Townley, who was born in Iowa, has lived in Chile for the last 20 years, and has retained his U.S. citizenship. He is married to a Chilean writer and has two sons.

According to press reports, he has been active in an organization of militant rightists who opposed the Marxist government of Chilean president Salvador Allende. Allende was overthrown by a military coup in 1973, and replaced by a government headed by Gen. Augusto Pinochet.

Letelier was a leading figure in the exile government opposed to the Pinochet government.

Two months ago, the U.S. government asked the Chilean government to produce for questioning there two persons who reportedly traveled to the U.S. using faked Chilean documents prior to Letelier's murder.

One of those persons later was identified as Townley, and the other has been identified as Capt. Armando Fernandez Larios. Both were questioned in Chile, but only Townley has been returned to the U.S. so far.