Two defendants in the Abscam bribery trial of Rep. Michael O. (Ozzie) Myers (D-Pa.) tried to con $25,000 out of an undercover FBI agent last September by presenting an impostor as the No. 2 man in the Immigration and Naturalization Service, according to testimony today.

But the agent, Anthony Amoroso Jr., balked -- apparently because he recognized that the impostor was too young to be the INS official -- and the scheme failed.

A 15-minute videotape of the Sept. 19 meeting in a Northwest Washington home was interrupted so often by laughter from the judge, jury and audience today that it could have been a pilot for "The Gang Who Couldn't Con Straight."

For instance, impostor Ellis Cook, a former law partner of defendants Howard L. Criden and Louis Johanson, was given the wrong name for the official he was impersonating, Mario T. Noto, then deputy commissioner of the INS.

Cook, who testified that he was "petrified" throughout the charade, said at one point on the videotape that his name was "Mario Nopo, N-O-P-O."

At another point, Melvin Weinberg, a convicted con man who worked as an undercover informant for the FBI during the investigation, warned that Amoroso, who was posing as the representative of an Arab "sheik," did not think Cook was old enough to be Noto. "How old is he supposed to be?" Cook responded.

Cook, who said he is cooperating with the government to avoid indictment for his role in the alleged Abscam "sting" conspiracy, testified that he was told a few days before the meeting that the "sheik" wanted to be able to get into the United States in case of a revolution in his homeland, and that he would pay $25,000 to an immigration official who could help him.

Criden and another codefendant, Mayor Angelo Errichetti of Camden, N.J., picked him to pose as the official, Cook testified.

This occurred less than a month after Criden, Errichetti and Johanson allegedly were involved in arranging a $50,000 payoff that they split with Myers, after the congressman promised to introduce a private bill to help the "sheik" with his immigration problem. Johanson and Myers were not involved in the alleged effort to con the FBI "sting" operation.

Cook said he was told ahead of time that both Weinberg and Amoroso would know he was posing as Noto. But he said that when he arrived he felt that Amoroso was not aware of the charade.

Criden's attorney, Richard Ben-Veniste, introduced the tape during cross-examination of Cook in an attempt to show that Weinberg was part of the scheme to con the FBI agent.

Defense attorneys have claimed that their clients had no intention of breaking conspiracy and bribery laws. Rather they said, the defendants had been fooled into acting out parts scripted by Weinberg.

In this instance, they suggested, Weinberg was working with Errichetti and Criden to take money from the "sheik."

The videotape of the meeting began with Amoroso explaining for the camera that he was expecting Noto and Errichetti and was placing $50,000 in $50 bills in a briefcase. The defense implied that Weinberg was to receive the other $25,000, but Cook said he had never been told that.

When Cook and Errichetti arrived, Amoroso told Cook: "Why don't you sit over there," and directed him to a sofa facing the camera.

"We don't get sofas like this at work. We sit in a chair," Cook said.

"Have you got a card, commissioner?" Amoroso asked Cook. The impostor replied that he did not because "I don't go out of the office to meet people. I'm in administration. I'm a civil servant."

Amoroso said it was his understanding that the INS official was to have brought an immigration application. Cook said he did not know which form would be needed.

Amoroso then asked Errichetti to step outside for a moment.

Weinberg, who is never seen on camera, then talked with Cook about immigration law. Cook suggested that the "sheik" might be able to enter the country as a "treaty merchant" if he had investments here. Weinberg explained that Amoroso -- whose undercover name was Tony DeVito -- was "scared someone is bringing a ringer in. We were told that this Nopo was an older man."

"How old is he supposed to be?" Cook asked.

In an apparent effort to calm Cook, Weinberg said: "We're scared too . . . You gotta be careful . . . You're takin' a chance, we're takin' a chance. We're talkin' one on one so it can't go any further."

A minute later Weinberg left the room and Cook sat silent and unmoving for nearly five minutes. He testified that he was afraid the "sheik" would kill him if he found out he was not an immigration official.

The silence on the tape was interrupted by what sounded like chimes marking the half hour. But a digital timer superimposed on the picture showed the time to be 14:24. Judge and jury broke into laughter.

Amoroso reentered the room to pick up the briefcase containing the cash. "Is this yours?" he asked Cook. "No it's not," Cook replied.

The meeting broke up a short time later and Errichetti and Amoroso can be heard off-camera discussing another meeting. The room remained empty for a few minutes. Then Amoroso reentered, retrieved his large cigar, stuck it in his mouth, and exited.