UPDATED: Joel Katz, one of the music industry’s most powerful attorneys and founding chairman of the Greenberg Traurig’s entertainment and media practice, has resigned “by mutual understanding” from the firm.

A rep for the firm declined requests for further information; sources tell Variety the move has been in the works for some time and Katz is planning to launch his own firm, bringing many of his clients with him. Another source said that Katz was the one who decided to leave the firm, partially because of Greenberg’s high fees, although a rep for Greenberg denied that account.

That source added that the firm is sending letters to Katz’s clients, offering them the opportunity to remain with the firm, but if they decide to go with Katz, they must put in a formal request in order to retrieve their files. Sources say these practices are standard and governed by Bar Association regulations. A Greenberg rep said Monday that “few” of Katz’s clients had requested their files.

Katz, 76, who is also an officer at the Recording Academy, was accused of sexual harassment by ousted president-CEO in a blockbuster legal complaint against the organization early last year. Before her ouster, Dugan also sent a memo to the Academy’s head of HR expressing concern about the organization’s “exorbitant and unnecessary” legal fees to outside law firms, including Greenberg Traurig.

According to 990 forms (for tax-exempt organizations) filed to the IRS by the Academy covering the tax years 2013-2017, the organization paid out nearly $15 million over those years to two law firms — Greenberg Traurig LLP and Proskauer Rose LLP — as well as millions in additional legal expenses. Those firms are headed by Katz and Chuck Ortner, respectively, both of whom have worked closely with the Academy, particularly former president/CEO Neil Portnow, for decades and also represent Academy executives and/or Board of Trustees members (including new interim president/CEO Harvey Mason, Jr., a Greenberg Traurig client).

While Katz led the negotiations for the Grammys’ 10-year, $500 million deal with CBS in 2016, the Academy has paid more than $1 million per year to Greenberg for other legal services, according to its tax records The Recording Academy has no in-house attorney or business affairs executive, choosing instead to pay outside law firms, apparently for all of its legal work. Reps for the Recording Academy did not immediately respond to Variety‘s request for comment.

Katz is also one of the music industry’s top and most entrenched lawyers, having represented many executives (including L.A. Reid and Republic Records’ Monte and Avery Lipman) over the years as well as artists including Michael Jackson, Justin Timberlake, Jimmy Buffett, Julio Iglesias, Willie Nelson and many others; he also was the chief negotiator for Scott Borchetta in the acquisition of Big Machine Records by Scooter Braun’s Ithaca Holdings. Sources tell Variety that both Katz and Ortner are also paid salaries as outside general counsels by the Academy, as well as expenses.

An announcement from Greenberg Traurig executive chairman Richard A. Rosenbaum reads: “Joel Katz has, by mutual understanding, resigned from the firm as of December 31, 2020. Our global entertainment practice remains strong, diverse and among the largest, most dynamic and highest rated in the world, led by Chair Bobby Rosenbloum in Atlanta, assisted by Vice Chairs Barbara Meili in New York and Dan Black in Los Angeles, as well as Jay Cooper, the founder of our Los Angeles Entertainment Practice, leading music industry lawyers Jess Rosen in Atlanta and Paul Schindler in New York, and many others. We thank Mr. Katz for his contributions over the years and have no further comment at this time.”