Kidnaped Belgian industrialist Baron Edouard-Jean Empain, 40, was released unharmed last night in one of Paris busiest squares.

Police said Empain was freed at 10:30 p.m. in the brilliantly lit Place de l'Opera facing the Paris Opera. The square was crowded with tourist visiting Paris for the Easter weekend.

Police said Empain appeared to be in good health.

Fears had mounted that Empain would be killed after police foiled an $8.6 million ransom pickup Friday night in a gunfight that killed one of the suspected kidnapers. Another gang member was wounded and captured in the shootout, and two policemen were slightly wounded.

Three other men in a getaway car exchanged shots with members of a special antimob police squad at the ransom drop site and then escaped.

The Baron was freed following an appeal from the captured suspect, Alain Caillol. It was not known if any ransom was paid.

Empain heads the Empain-Schneider group, one of Europe's largest industrial empire. He was siezed Jan. 23 by five gunmen outside his luxurious Paris apartment and the kidnapers later threatened to kill him if a multimillion-dollar ransom in Swiss francs was not paid.

The kidnapers immediately sent proof to Empain's family that they were holding him. A handwritten note from the baron, his identity card and a slice fron the left little finger, presumably Empain's.

Empain's family had indicated it would pay a ransom. Investigators said the abduction was the work of common criminals and not political terrorists.

The Empain-Schneider group, which includes about 150 businesses that manufacture products ranging from nuclear power plants to electronic hardware, did an estimated $4.5 billion worth of business last year.

Police said, Empain's family arranged the ransom package and a representative drove with the money Friday to a prearranged drop point at a telephone booth beside a major highway just south of Paris.

But police, concealed in a truck, were waiting at the site. They said that as the family representative approached the phone booth, two masked men ordered him back into the car and they then drove about 500 yards before police ordered them to stop and open fire.

The family aide was not wounded and the ransom money was recovered, but one of the masked gunmen, Daniel Duchateau, 39, was killed. Caillol, 36, was slightly wounded.

Officials reports that Caillol provided information about the three men who escaped . Caillo was charged with being an accomplice to an illegal detention.

Police said that when Empain was released he telephone his wife from the Place de l'Opera and she immediately called police. The baroness drove quickly to the spot where her husband told her to meet him and police arrived soon after.

After Empain was kidnaped, French police set up a heavy netwoks of road blocks. President Valery Giscard D'Estaing and Belgium's King Baudoin, both freinds of Empain, were kept informed of every development in the case.