Former Morris County Prosecutor Robert Bianchi has formally resigned his post, ending a legal battle in which he sought to remain in the position.

Bianchi announced his resignation in a two-sentence letter sent to Gov. Chris Christie this week. It took effect Friday.

Bianchi also said he's withdrawing a lawsuit he filed late last year to retain his position. The legal filing came just days after Christie had Bianchi removed from office, six months after his term expired.

The Republican governor had nominated Fredric Knapp to the job in June 2012. But when the Legislature failed to act on the nomination, Knapp was sworn in as an assistant attorney general and as acting prosecutor.

Bianchi plans no further public statements about his resignation and will announce his future plans "shortly."