A Bronx cop pleaded guilty in the police ticket fixing scandal today and became the first senior PBA official to fall victim to the wide-ranging investigation, police sources told The Post.

Gregory Manning was docked 40 days vacation, given a 5-day suspension and slapped with a $500 fine for his role, the sources said.

Manning testified several times before a Bronx grand jury investigating reports of the fixing of tickets and arrests by dozens of cops.

He was granted immunity from criminal prosecution and pleaded guilty today to departmental charges in the NYPD’s Advocates Office at One Police Plaza.

Manning had been the financial secretary of the police union in The Bronx until last month, after losing his reelection bid.

Manning, a cop since 1988, had filed papers to retire, speeding up the charges against him.