Billy Corgan has weathered many break-ups, from parting ways with former bandmembers and managers to firing PR firm MSO, which he did in November after nearly 10 years of service. But his current incarnation of The Smashing Pumpkins is allegedly at the center of another big split: the dissolution of the 25-year business relationship between Peter Katsis and Jeff Kwatinetz, who have managed such acts as Limp Bizkit, Enrique Iglesias, 30 Seconds to Mars and Puddle of Mudd at Prospect Park and previously The Firm over the years together.

Katsis, a Prospect Park partner, signed The Smashing Pumpkins to the company's music management roster in 2012. The band joined longtime Katsis clients Jane's Addiction, Perry Farrell and Korn, but, according to a Prospect Park colleague, garnered most of Katsis' attention. "Peter was spending 90 percent of his time on the Pumpkins" -- a characterization Katsis disputes -- despite an active roster that included the successfully reunited Backstreet Boys, Ice Cube, Eden xo and recent signee Azealia Banks, who released her long-shelved Broke With Expensive Taste album through the firm's label-services division in November.

Billy Corgan Says Next Smashing Pumpkins Album Is 'The End'

Sources describe a "concerned" Kwatinetz who intercepted Katsis while mid-flight to a Pumpkins European promotional tour in early December. One such insider says Kwatinetz -- who removed himself from day-to-day music management in 2013 to focus on the company's now-bankrupt digital-TV department -- sent a series of heated emails urging Katsis to return home early. (Kwatinetz also had pulled Katsis away from much of the Pumpkins' U.S. promo circuit in support of December's Monuments to an Elegy album, which could have benefited from an awareness boost: The set was the first Pumpkins album since 1991's Gish to debut outside the top 10.)

Kwatinetz eventually fired his partner for cause and failure to comply with company directives, sources say, and blocked him from doing business with the firm's acts. In addition to music, Prospect Park has a TV production arm with more than 10 shows in development.

"I have always strived to give my best efforts to every artist I have ever worked with," Katsis tells Billboard in a statement. "That is the kind of commitment we owe to each of our artists if we want to be great managers. I feel strongly that I gave that effort to every artist while at Prospect Park -- and of course especially when they were about to start big tours, or release great new music. It doesn't matter if it was Azealia Banks and the Smashing Pumpkins this fall, or Backstreet, Jane's and Korn in year's before. It is really unfortunate that we have had this disagreement, because I loved Prospect Park. This year was tough for a number of reasons, but as a partner in the company I could not have been more surprised that it came to end like this."

The partners' future business relationship is in limbo -- one insider says, "I don't see how either can be successful without the other" -- as is the state of the firm's offices: The remaining staff has been telecommuting since late December while Kwatinetz seeks a new space in Los Angeles. He declined to comment for this story, as did a representative for Corgan.

An edited version of this article first appeared in the Jan. 24 issue of Billboard.