The superintendent of the Los Angeles Unified School District resigned on Sunday, months after the F.B.I. raided his home and office in February in connection with a criminal inquiry into the district’s dealings with an A.I. start-up.

The superintendent, Alberto Carvalho, was a well-known education leader who was hired in 2021 to lead the nation’s second-largest school district. He had been on paid leave since Feb. 27, when the board of education suggested he step back to quell mounting turmoil over the investigation.

It was not immediately clear who would replace him. A veteran Los Angeles Unified administrator, Andres Chait, has been the acting superintendent since Mr. Carvalho’s paid leave began.

Mr. Carvalho’s resignation, which was effective immediately, was conveyed in a letter to the district and members of the school board.

Mr. Carvalho did not immediately respond to a request for comment.

The school board plans to meet on Wednesday to discuss its next steps.

This is a developing story. Please check back for updates.