NEW YORK (AFP) - Wall Street conman Bernard Madoff was led handcuffed to jail Thursday after pleading guilty to tricking thousands of people out of billions of dollars in one of history's biggest financial scams. Madoff, 70, told a packed New York court he was "deeply sorry and ashamed" for the decades-long Ponzi scheme and the former financial titan and chairman of the Nasdaq stock market now looks likely to die behind bars. He faces a maximum sentence on June 16 of 150 years after pleading guilty to all 11 counts of fraud, perjury and theft. Prosecutors also want to track down an astounding $177b they say passed through Madoff's hands. Judge Denny Chin asked Madoff, wearing a grey suit, dark tie and white shirt, how he would plead. "Guilty," Madoff replied. Defence lawyers said the silver-haired money manager should be allowed to remain free on bail in his seven-million-dollar Manhattan apartment until sentencing. But Chin responded: "It is my intention to remand Madoff," triggering applause from victims who had gathered in the courtroom. Federal marshals then handcuffed Madoff behind his back and led him away. Madoff looked nervous when he first entered the court, watched from the packed benches and via video link by hundreds more people in a separate room. He clasped and unclasped his hands, fidgeted with his chair, and answered questions from the judge in a barely audible voice. But he appeared to gather confidence after Chin asked him to recount his crimes. Speaking publicly for the first time since his shocking arrest on December 11, Madoff recounted how he lured clients to give him their money. They believed he was making legitimate investments, when in reality he was running a Ponzi scheme where the funds invested by new clients are used to pay fake returns to existing clients. He said he was sorry and that he had never intended to perpetuate such an epic fraud. "I believed it would end quickly and I would extricate myself and my clients," he said. "This proved difficult and, in the end, impossible." "I cannot adequately express how sorry I am," he added, saying: "I am here today to accept responsibility for my crimes." Madoff was also forced for the first time to listen to some of his victims, with three being allowed by Chin to address the court. All argued passionately that the government must do more to uncover the scope and details of Madoff's fraud. "He didn't do these crimes alone and I don't understand why conspiracy is not one of his pleas," one said. "Who handled it when he was gone?" Two others begged Chin not to accept the guilty plea and to force Madoff to stand trial. "If we go to trial we have more of a chance to comprehend the global scale of this horrendous crime," one said. "We will bear witness to the pain that Madoff inflicted on the young, the infirm and the old." Prosecutors and Chin himself on Thursday stressed that the case remains open.