INDIANAPOLIS — Oliver L. North announced on Saturday that he would not serve a second term as the National Rifle Association’s president, deciding to step down as the organization grappled with a bitter dispute over its future and its worst leadership crisis in decades.

He made the announcement as the N.R.A. faced a challenge from the New York attorney general, Letitia James, who had opened an investigation into the gun group’s tax-exempt status.

On Friday, Ms. James’s office sent letters instructing the N.R.A. and affiliated entities, including its charitable foundation, to preserve relevant financial records. Some of the N.R.A.’s related businesses also received subpoenas, according to people with knowledge of the inquiry. Both the attorney general’s office and a lawyer for the N.R.A. confirmed the investigation.



The move by Ms. James came amid a stunning internal power struggle that took a major turn on Saturday when Mr. North, in a letter that was read on his behalf at the N.R.A.’s convention, said he would not be renominated. He and insurgents in the N.R.A. this past week had been trying to oust Wayne LaPierre, the group’s longtime chief executive.