While it remained unclear whether the new arrivals will be anointed as partners in their new Beverly Hills digs, the move is a huge boon to Endeavor.
The Endeavor partner roster swelled to 24 recently following the arrival of TV agent Marc Korman.
Ben Stiller and possibly Jack Black are expected to follow the agents over to Endeavor. Crucially, the trio currently represents Judd Apatow, the talent behind the latest wave of comedy hits such as Superbad, Knocked Up, The 40-Year-Old Virgin and the upcoming Forgetting Sarah Marshall, although it was not clear whether the writer-director-producer was also jumping ship.
Other talent clients include Jonah Hill, Patrick Dempsey, Owen Wilson, John C Reilly and UK comic Steve Coogan, who may be on the cusp of his long awaited first US hit when Focus Features releases the Sundance hit Hamlet 2 on August 22.
Stevens had been at UTA since the agency's inception and had grown increasingly uncomfortable with working arrangements at the company. Sheinwold joined 15 years ago and Hallerman started 12 years ago as Stevens' assistant.
In recent years UTA has been haemorrhaging talent and agents. Will Ferrell and Jim Carrey famously departed for CAA, and Vince Vaughan made the same move several weeks ago.