Barry Diller has told members of the Live Nation board that he plans to resign as chairman.

Though sources said there was a clash between Diller and other board members over control of the music behemoth, Diller said in a statement, “I have always said, since the merger of Ticketmaster and Live Nation, that I only planned to stay as chairman through the transition and integration of the two companies. It’s been almost a year and I informed the board today that while there was no rush, the board should start the process now to appoint a new chairman.”

The effective date of the resignation remains unclear.

Diller, who plans to remain on the board, did not respond to a request for comment on the reported clashes with board members including Irving Azoff, now the top executive at Live Nation; Ari Emanuel of WME; and Mark Shapiro, former CEO of Six Flags; as well as Live Nation CEO Michael Rapino.

Sources confirm to Billboard.biz that it was widely known the chemistry between Azoff and Diller left something to be desired, and there was speculation by many insiders the announcement might have been made even earlier.

The developments at a Tuesday board meeting spring from a power struggle over control of the music industry giant created this year when Live Nation and Ticketmaster merged in a deal valued at $889 million.

Diller’s decision appears to represent a rupture with one-time associate Azoff, who may now assume the chairmanship. Azoff declined to comment.

Ticketmaster spun off IAC in the summer of 2008, with board members including then-Ticketmaster chairman Terry Barnes, Ticketmaster president/CEO Sean Moriarty, and IAC chairman Diller. By November of that year, Ticketmaster acquired Azoff's Front Line Management. In February of 2009, the Ticketmaster/Live Nation merger was officially announced, and by March Moriarty resigned as CEO and the TM board of directors.

After a year of intense scrutiny, the Department of Justice approved the merger in January, with the structure of Michael Rapino as CEO/president of Live Nation Entertainment and Azoff as executive chairman of Live Nation Entertainment and CEO of Front Line. Diller was named chairman of the board of Live Nation Entertainment; the board consisted of 14 directors, seven from each company.

Soon after the merger, according to a source, Diller and other board members began clashing over control. Sources said Diller tried to replace a chief financial officer who enjoyed solid support from top executives and other board members, but that attempt was rebuffed.

As time went on, some on the board became increasingly resentful and suspicious of Diller’s agenda, according to an informed source. They believed that Diller wanted to wrest control of some board seats to cement his control of the company and decided to oust him instead.

Before that could happen, this source said, Diller said he planned to resign.

Though Live Nation and Ticketmaster were fierce competitors for a year after Live Nation left Ticketmaster and formed its own ticketing division in 2009, since the merger was approved the Live Nation side of the business has increasingly steered the course of the Ticketmaster division, with former Live Nation Ticketing CEO Nathan Hubbard tapped as CEO of Ticketmaster earlier this year. Several longtime Ticketmaster executives, including former executive VP of North American business operations Mike McGee, exited the company. Barnes is now in a consultant role but is no longer involved in day-to-day operations.

Hubbard and his team restructured the long-held regional operational setup of Ticketmaster into one broken down into various business segments, and also has focused heavily on tapping into the power of the vast Ticketmaster database. Ticketmaster is facing stiff competition today from a wide range of Internet-based startups, as contracts with venues, promoters, sports teams and others expire and the barriers to entry into the ticketing space fall.

While Azoff and Diller have known each other since the '70s, Diller's relationship with Ticketmaster dates back to 1997 when Diller's Home Shopping Network acquired 50% of Ticketmaster; by 2002, what became IAC owned all of Ticketmaster, spinning the company off (along with several other companies) into an independent entity six years later.

Diller's role in the merged company has been hard to pin down. When plans for the merger were first announced, Diller was vocal to shareholders about the promise the combined companies held. In this summer's much-analyzed investor meeting, however, Diller did not play a role.

Additional reporting by Ray Waddell