John W. Gacy Jr., who reportedly has confessed to 32 sex-related slayings, entered innocent pleas yesterday to each of seven murder charges contained in a grand jury indictment.

Gacy, 36, stook silent and expressionless as his attorney, Sam Amirante, pleaded innocent in his behalf before Circuit Court Judge Richard J. Fitzgerald.

The judge ordered that Gacy be examined to determine his competency to stand trial and whether he was sane at the time the slayings took place. But he did not rule on a defense motion to quash the indictments. Amirante argued that the grand jurors' judgment must have been tainted by news accounts of the slayings.

Amirante also asked that searches be discontinued at Gacy's house in an unincorporated, residential area just northwest of Chicago.

Cook County sheriff's investigators have found the bodies and skeletal remains of 26 young men beneath the floor of Gacy's house in excavations begun Dec. 21, when the stocky building contractor was arrested.

A 27th body was found buried beneath Gacy's garage, and two more bodies which investigators say are linked to Gacy have been pulled from the Des Plaines River.

A 30th body may also be linked to Gacy, authorities say. The body of Timothy O'Rourke, 20, of Chicago, was found in the Illinois River near Morris on June 30. The area is about three miles west and downstream from where the other two Gacy-related bodies were pulled from the water.