The weekend defection of agents Nick Stevens, Sharon Sheinwold and Lisa Hallerman from UTA to Endeavor has raised questions about UTA’s viability and has focused attention on the battle among talent agencies to control the lucrative film comedy arena.

Hours after co-owner Stevens and partners Sheinwold and Hallerman told UTA they would be crossing Wilshire Boulevard to go to Endeavor, both agencies were dealing with the repercussions.

The short-term focus was on clients, and the long-term focus will be on how UTA gets on without the trio. Also of note will be how Endeavor absorbs three strong personalities into a partnership roster that grew to 24 just weeks ago when former UTA television partner Marc Korman arrived.

Stevens, Sheinwold and Hallerman were either primary agents or worked on teams that repped much of the talent that were the rubber of UTA’s vaunted “comedy wheel,” a system in which emerging talent rolled into vehicles driven by established laffer stars.

Ben Stiller is following Stevens to Endeavor, and Sheinwold client Jack Black was considered likely to leave. Others in play include Judd Apatow, Jonah Hill, Patrick Dempsey, Jason Bateman, Steve Coogan, Jason Lee, John C. Reilly, Paul Rudd, Jason Schwartzman, Jason Segel; directors Frank Coraci, Amy Heckerling; and current “Saturday Night Live” cast members Amy Poehler, Fred Armisen, Will Forte, Bill Hader, Andy Samberg, Kristen Wiig and Casey Wilson.

Perhaps the biggest name on that list is Apatow, because he generates so many films as writer, producer and director. It’s noteworthy that he didn’t go to CAA when one of the agents on his team, Dan Aloni, left his post as UTA partner to go there.

Some discounted an Apatow exit now with Stevens because of the frosty relationship that Stevens has had with Apatow manager, Jimmy Miller ever since Jim Carrey left UTA and went to CAA.

Apatow’s point person at UTA is David Kramer, considered one of UTA’s top dealmakers.

Aside from Stevens, Hallerman, Sheinwold and Korman, Endeavor’s partnership roster already consists of UTA alumni Adam Isaacs, Brandt Joel (who broke in as Stevens’ assistant) and Elyse Scherz.

Stevens has long boasted that his style was not to sit in the office all day holding hands. He preferred to be on movie sets with clients, or wheel and deal from the golf course. UTA decided that management by Blackberry wasn’t good enough and after it began meetings to redefine the current situation, Stevens made the move.

Endeavor hasn’t said yet whether all three newcomers will become partners, and speculation is that while Stevens is the biggest name and most senior manager of the trio, he might prefer to limit his responsibility to repping his clients.

UTA chairman Jim Berkus said he will run the talent department with longtime senior partners David Guillod and Tracey Jacobs.

Berkus knows that aside from client retention, one of his major battles now is that of perception. Immediately after word leaked of the troika’s defections, rumors raced that UTA might merge with Paradigm. Both agencies flatly denied anything was going on, and it strained logic that such a vast undertaking would be under way less than 48 hours after the surprise exit of the trio.

“We’re not for sale, we’re not merging or even talking to people,” Berkus told Daily Variety. “We’re building UTA, and we believe in it. We have a great company with great agents, and we’ll continue on our path.”

Berkus said that while the defection of the agents and any clients would certainly be painful, it was something the board factored in when it made the decision to engage Stevens to change his leadership role at the agency.

“Nick has been at UTA almost from its inception, and he’s run the talent department for something like 14 years,” Berkus told Daily Variety. “We’ve enjoyed great success with him. But over the last few years, his view of how to run the business of UTA, especially talent, and our view, began to diverge. And it became untenable in the last few months. We engaged in a series of conversations about making some fundamental changes in his role in the management of UTA. After a round of those conversations, he decided rather than make the changes we wanted, he preferred to leave. We were prepared for that eventuality, though it wasn’t our preference.”

Berkus said the agency would deal with the fallout and move on.

“We obviously will lose some clients, but we’re comfortable with our decision,” Berkus said. “We have some unbelievably talented young agents who do share our vision of the talent department. This is an opportunity to come together and thrive. We know we’re going to become a stronger and more effective UTA because of it.”

By Sunday, all three agents were finalizing their exits. Stevens’ departure is the most complicated. It was thought likely that some negotiation regarding his contract, and ownership stake, would be ironed out before he can leave. That situation was expected to be cleared up within the next few days.