Former Reagan advisers John Poindexter and Lt. Col. Oliver North and two others pleaded not guilty Thursday to the sweeping indictment charging them with conspiracy, theft and obstruction of justice in the Iran-Contra scandal.

Led by Poindexter's plea of "not guilty," the four men charged last week in the massive 23-count indictment in turn declared their innocence at an arraignment hearing before U.S. District Judge Gerhard Gesell.Before the hearing started, Poindexter and North greeted each other in the courtroom with an warm embrace.

Gesell, 77, ordered the men to go free without bond and kicked off what will be months of tangled legal proceedings before any trial date can be set.

Appearing with Poindexter, President Reagan's former national security adviser, and North, who announced his retirement from the Marine Corps last week, was retired

Air Force Maj. Gen. Richard Secord and his business partner, Albert Hakim. Fifteen attorneys attended the defendants.

The arraignment before Gesell, who presided 15 years ago over several aspects of the Watergate scandal, could be one of the few occasions the four men appear together in court for months.

Each defendant in President Reagan's worst political crisis is charged with conspiring to defraud the government by diverting millions of dollars in profits to the Nicaraguan Contra rebels from secret U.S. arms sales to Iran.

Independent prosecutor Lawrence Walsh, who investigated the foreign policy scandal for 15 months, told Gesell that he had no objection to the four men being released on their personal recognizance.

Before the hearing, North entered the U.S. courthouse through a side door; Poindexter came in through the front and offered only a terse "good morning" to reporters.

Outside, about two dozen supporters of the Marine demonstrated, carrying signs saying, "Ollie North American hero," and "Duty, honor, country punishable offenses?"

But a lone protester in front of the courthouse carried a black banner saying, "Reagan and Bush sell `crack' to fund the Contras."

If convicted, North faces a maximum 85 years in prison and $4 million in fines; Poindexter, 40 years and $1.75 million; Secord, 29 years and $1.5 million, and Hakim, an American citizen, 27 years and $1.25 million.