The Philadelphia district attorney's push to dump cases connected to controversial narcotics officers entered a new phase Wednesday as prosecutors withdrew charges against 37 accused drug dealers in just one courtroom.

Court officials said they expected an additional 61 cases to be withdrawn as early as Friday, and one judge on Wednesday dismissed charges against an alleged major dealer who was initially held on $2 million bail.

Six members of the Philadelphia Police Department's aggressive Narcotics Field Unit were transferred last week after District Attorney Seth Williams declared that he would not use them in drug investigations in any capacity.

Wednesday's dismissals add to approximately two dozen cases involving the officers that have been thrown out since Dec. 3, when Williams sent Police Commissioner Charles H. Ramsey a letter stating his position regarding the officers.

The previous cases had been tossed at the lower Municipal Court level; most of Wednesday's cases were before Common Pleas Court.

More than 350 cases are pending against suspects arrested by the officers, court records show. And scores - possibly hundreds - of other cases in which defendants have been convicted could be appealed, according to defense lawyers involved.

In most of Wednesday's cases, judges had already ruled that there was sufficient evidence to try the suspects. But prosecutors were unwilling to proceed.

During a brief hearing before Common Pleas Court Supervising Judge Sheila Woods-Skipper, who heard the cases of the 37 defendants that were withdrawn, defense lawyers said they were stunned by the speed of the dismissals.

"It was a 30-second procedure," said Carmen C. Nasuti 3d, one of the lawyers who had a case dismissed.

Courtroom prosecutors said they were taking the action based on "prosecutorial discretion . . . in the interest of justice," he said.

Tasha Jamerson, a spokeswoman for Williams, said most of Wednesday's cases involved defendants who were in jail.

It is unclear how many of the suspects walked free and how many stayed in jail on other charges.

The cases all involved Officers Michael E. Spicer, Thomas Liciardello, Brian P. Reynolds, Perry Betts, and Brian Speiser, who had worked in Narcotics Field Unit South.

The five and their supervisor, Lt. Robert Otto, were transferred to lower-profile units.

Williams has yet to give a reason for his action, but sources close to the cases said he apparently had lost confidence in the officers' credibility.

Although Otto, a unit supervisor, was also transferred, records show he had made very few arrests.

Common Pleas Court President Judge Pamela Pryor Dembe praised Williams' action.

"This certainly is the right thing to do," she said, adding that computerized court records helped prosecutors and defense lawyers identify cases that should be dismissed.

As in past police scandals, many of the defendants now winning in court have long rap sheets, often with multiple drug arrests.

Among the suspects whose drug cases were tossed Wednesday were:

James Grimes, 21, of Philadelphia, an accused murderer with six previous arrests whose 2009 drug charges were dismissed. He is still being held without bail for an April homicide arrest.

Waldo Reinoso, 25, of Frankford, who has eight arrests, including for attempted murder, aggravated assault, and drugs.

Lester Howard, 42, of South Philadelphia, who has 24 previous arrests and who has been sentenced to prison 12 times for such crimes as drug offenses, theft, and assault.

Luis Valle, 49, of Philadelphia, who had seven drug convictions and who has been in and out of prison since 1998.

Anthony D. Brown, 37, of Philadelphia, who has been in and out of prison for drugs and other charges.

Aaron Dixon, 30, of Philadelphia, a convicted drug offender with nine previous arrests.

Lamar Amaker, 27, of West Philadelphia, a two-time convicted drug offender.

Thomas Santiago, 30, of Philadelphia, who has nine arrests and two drug convictions.

Municipal Court Judge Michael Erdos on Wednesday dropped firearm and drug charges against Kit Poon, 42, who was arrested in North Philadelphia this year with what authorities said was a large amount of marijuana.

Poon's bail, which had been set at $2 million, was reduced to $300,000, and he was released after posting a 10 percent bond in March.