CARACAS, Venezuela (AP) _ A Venezuelan appeals court today upheld the acquittal of Orlando Bosch in planning the 1976 bombing of a Cuban airplane that killed 73 people.

Bosch, a Cuban exile and an opponent of Cuban President Fidel Castro, has been jailed for 10 years in the protracted court case.

He could be freed within a few days after the court formally reads the decision, although the Attorney General's office is expected to appeal the decision to the Supreme Court.

The special three-judge panel of the Eighth Superior Penal Court also upheld the homicide convictions of two of his co-defendants, Venezuelans Hernan Ricardo and Freddy Lugo, in the bombing. Their acquittal by the lower court on charges of treason was upheld. It was the third ruling in favor of Bosch, a 59-year-old physician, in the case. Despite the earlier acquittals, Bosch was never released from jail.

A military judge acquitted the three in 1980, but his decision never was ratified by a higher court and the case was returned to the civilian court for retrial.

In July 1986, Bosch was acquitted again and his co-defendants were convicted and sentenced to 20 years each for the Oct. 6, 1976 bombing of the Cubana de Aviacion airliner, but the verdicts were set aside by a judge and sent to yet another court.

The plane, on a commerical flight from Venezuela to Cuba, blew up shortly after taking off from a stopover in Barbados, killing all 73 people on board.

Most of the passengers were Cuban athletes returning from a fencing tournament in Caracas.

Bosch and three others were jailed within weeks of the incident.

Venezuela claimed jurisdiction on grounds that three of the four defendants were Venezuelan.

The fourth defendant, Luis Posada Carriles, a nationalized Venezuelan from Cuba, escaped from a Venezuelan prison in 1985, and has not been found.

The lengthy legal process led to a chill in relations between Venezuela and Cuba, which demanded the four be tried and convicted. Relations improved after both countries backed Argentina in its war with Britain over the Falkland Islands in 1982.