Alan J.Arnone, the 24-year-old Maryland man accused of the brutal 1976 murder and robbery of Ronald J. Pettine at the Iwo Jima Memorial, testified yesterday he kicked Pettine only after his two companions had threatened to kill him if he didn't.

"They yelled at me and told me to come over, they told me to come and kick him," Arnone told an Arlington jury. "I was afraid of what Chuckie (Bamman) might do to me. He said, 'if you don't kick him, I'll kill you."

Arnone said he then kicked the kneeling man a volunteer worker for the presidential campaign of Rep. Morris Udall, "once or twice" in the ribs.

Arnone took the stand in his defense after prosecution witness testified that Arnone had admitted, in writing and in oral statements, to participating in the beating that left Pettine dead on Oct. 2, 1976.

Arnone said he and two other men, Michael G. Simoneau, 18, of Falls Church, and Charles A. Bamman, 22, of Arlington, encountered Pettine, a married man with two children, in a wooded area near the memorial, known as a nighttime meeting place for homosexuals.

In testimony Monday, two male prosecution witness said they engaged in sexual activities with Pettine just before the incident.

In a slow, deliberate tone, Arnone told the court yesterday that on the evening of the murder, the three men left a party in Arlington and walked to the memorial where "a homosexual approached Chuckie."

"Chuckie started hitting him and the man bit Chuckie," Arnone said. "That made him crazy and he started beating on him harder. He picked up a stick (and hit him). Mike came over and he started hitting him. I kicked him onced or twice."

Arnone said the two men then pulled Pettine's clothes off and threw them into the woods. They dragged Pettine's body to a nearby creek bed where they further abused it sexually.

Simoneau is currently serving a 35-year sentence in connection with the case. Bamman, accused of striking Pettine with a tree limb and fracturing his skull, pleaded guilty to first degree murder and received a 40-year sentence.

William D. Dolan, Arnone's attorney, centered his defense yesterday around the nature of the relationship between the 4-foot 9-inch tall Arnone and the two men.

At the time of the slaying, Arnone was living with Simoneau, his cousin, in Falls Church.

Paul Bombacci, an Arlington County housing specialist who was a parttime recreation director of the Dawson Terrace Recreation Center where the three men would occasionally meet during the summer of 1976, said Arnone "followed Mike (Simoneau) and some other guys like a little puppy ever they asked of him."

Bombacci said Arnone "looks up" to the 6-foot1-inch tall Bamman "as a strong guy who could lick the world." But Arnone later testified that two months prior to the slaying, Simoneau and Bamman had sexually abused him. "It's embrassing," said Arnone, describing the incident. "I fought [Chuckie] back but I was afraid he'd hurt me." Arnone said it was the memory of this incident that forced him to later kick Pettine.

Under cross-examination, Assistant Commonwealth's Attorney Kenneth Melson asked Arnone if the crime or run away. Arnone replied, "No."

Earlier, James Harrell, a friend of the three charged in the murder, told the jury he accompanied Arnone, Bamman and another man to the memorial two months before the incident "to rough up the homesexuals there. But after Chuckie hit two men, we ran away," Harrell said.

Closing arguments are expected to be heard in the case today.