A Philadelphia man accused of planning to pay the victim of a 2008 armed carjacking $20,000 not to cooperate with prosecutors pleaded not guilty in federal court yesterday.

Michael Edwards, 31, who is in federal custody, is charged with conspiracy, carjacking, using a firearm during a crime of violence and witness tampering.

If convicted on all counts, Edwards faces a mandatory minimum of 10 years behind bars.

Authorities said that on Aug. 20, 2008, Edwards and co-defendant Christopher Sagias carjacked a 1980 Chevy Malibu owned by "M.B.," stole $200 and his cell phone at gunpoint and later tried to sell the vehicle back to M.B. for $2,200.

During the carjacking, Edwards pointed an AK-47 assault rifle at M.B., the indictment charged.

M.B. was not hurt and later identified Edwards from a photo lineup.

Edwards was arrested by Philadelphia cops last Dec. 15, and charged with robbery, aggravated assault and related offenses in connection with the carjacking.

While Edwards was in state custody, court papers said, he made numerous phone calls (or told others to do so) to Sagias and Jerry and Tina Edwards, his brother and sister, to enlist their help in keeping M.B. from cooperating with prosecutors.

The Edwardses have been charged with conspiracy and witness tampering in the case.

The indictment charged that Michael Edwards phoned Jerry Edwards on Jan. 28 and discussed having two unidentified individuals go and talk with M.B.

On May 28, authorities said, Michael Edwards called another unidentified person and had her call Sagias on a three-way call. During this call, Edwards and Sagias discussed paying M.B. $20,000 not to cooperate with prosecutors. The indictment charged that in July Tina and Jerry Edwards drove to M.B.'s residence and Tina attempted to pay M.B. the money.

Sagias, who was arrested in August, pleaded guilty last week to conspiracy, carjacking and related offenses. Jerry Edwards and Tina Edwards, both arrested last month, have pleaded not guilty.