Gordon D. Fox, speaker of the Rhode Island House of Representatives, resigned his leadership post on Saturday and said that he would not seek re-election in the fall, a decision that came a day after federal and state law enforcement authorities raided his office and home.

Mr. Fox, a Democrat, said in a written statement that he was abandoning the speakership he has held for the last four years because he did not want the raids to distract his colleagues from addressing the challenges the state faces.

“My personal focus going forward will be on my family and dealing with the investigation,” he said. “Because of the nature of this matter, I will not be commenting further.”

Federal and state law enforcement agents raided Mr. Fox’s office at the State House and his home in Providence, R.I., on Friday, but did not disclose the reason for the raids. Mr. Fox, too, has been silent on the raids.