A Bronx assemblyman says he is resigning from office and that his cooperation with prosecutors led to charges against a colleague in a federal bribery case.

Assemblyman Nelson Castro said he’s giving up his seat effective Monday.

Federal prosecutors say Assemblyman Eric Stevenson, another Bronx Democrat, was arrested in a bribery investigation involving another unnamed assemblyman charged with crimes who cooperated with the understanding that he would resign his position with the arrests of Stevenson and four other defendants.

Castro, elected to the Assembly in 2008, says he was indicted a year later for perjury from an earlier civil case and agreed to cooperate with Bronx and federal prosecutors “in conjunction with various investigations aimed at rooting out public corruption.”

He named no other cases in a statement Thursday.

(AP)