A divided U.S. Court of Appeals panel ruled yesterday that a federal prosecutor assigned to investigate antiwar activists in the late 1960s and early 1970s must stand trial in a $1.8 million civil suit for damages brought by 12 activists in Florida.

In a 2-to-1 decision, Senior Judge David L. Bazelon overturned a 1980 decision by a U.S. District Court judge who had dismissed the suit against Guy L. Goodwin, 53, a lawyer now assigned to the Justice Department's general litigation section.

The suit involved a claim by members of Vietnam Veterans Against the War that Goodwin, who headed a unit created by the Nixon administration to prosecute crimes by "revolutionary terrorists," lied under oath to a judge during a grand jury investigation of VVAW's alleged plans to disrupt the 1972 Republican National Convention in Miami.

A Florida judge had asked Goodwin if there were any government informants among a group of VVAW members who were then fighting their grand jury subpoenas. Goodwin said there were not. In fact, one VVAW member was a paid government informant.

The VVAW members sued Goodwin and other federal investigators, claiming their constitutional rights to effective legal counsel had been violated because Goodwin's alleged false statement led them to discuss legal strategy with their lawyers in the presence of the informant, who later passed on that information to the FBI.

Eight of the 12 activists were later indicted on the conspiracy charges but acquitted after a jury trial. The other four were convicted of contempt when they refused to testify. Those convictions were later overturned.

The suit against Goodwin began in 1973. In 1978, the U.S. Supreme Court allowed to stand a lower court's ruling that Goodwin did not have absolute immunity from prosecution.

U.S. District Court Chief Judge Aubrey E. Robinson Jr. later ruled that Goodwin was acting in good faith when he responded to the Florida judge's question, but Judge Bazelon ruled that a jury must decide that question. Goodwin yesterday declined to comment on the case.