A Manhattan federal magistrate judge has ruled that a legal malpractice claim may proceed against a law firm for failing to bring defamation claims on behalf of a client in a high-profile sexual harassment and discrimination case.

Kenneth P. Thompson of New York-based Thompson Wigdor & Gilly represented Michelle Joyce and Kimberly Osorio in a 2005 suit filed against hip-hop magazine The Source. Osorio, the magazine’s former editor-in-chief, and Joyce, a former marketing executive, alleged pervasive sexual harassment and a hostile work environment.