Aon this week filed a lawsuit against rival Alliant Insurance Services for an alleged “unlawful raid” of senior leaders and other employees of Aon’s facultative reinsurance group.

Aon claims Alliant took 26 of its employees, reinsurance business and confidential information as Alliant looked to get into the reinsurance market and “jumpstart the launch of Alliant Re, Alliant’s own reinsurance division and a new Aon competitor in the facultative reinsurance broking industry.”

Alliant Insurance Services announced on April 25 the launch of Alliant Re, its reinsurance brokerage division. Aon alleges the “premeditated” poaching of 32 percent of its reinsurance group’s employees, including the entire team in Chicago, began on April 19. The group that headed to Alliant included Nicholas Ambriano, the former leader of Aon’s U.S. facultative reinsurance group.

“The former employees misused their positions at Aon to, with Alliant’s encouragement and direction, covertly orchestrate the raiding of 26 Aon employees, Aon’s top U.S. facultative reinsurance clients, and Aon’s confidential and trade secret information to form a new competing business — Alliant Re,” the suit says. “Defendants did so in deliberate disregard of the former employees’ contractual duties and fiduciary obligations to Aon and with an intent to interfere with Aon’s business.”

“Alliant Re would not exist but for defendants’ theft of Aon’s employees, clients and information that Aon developed over decades,” according to Aon.

In a statement sent to Insurance Journal, Alliant said it “will vigorously defend against Aon’s allegations concerning the departure of employees from Aon’s U.S. Facultative Reinsurance group.”

This is not the first time Alliant has been sued by a competitor for allegedly stealing employees. Arthur J. Gallagher last year in a suit against Alliant said Alliant faced more than 40 lawsuits in dozens of jurisdictions from the likes of Aon, Lockton, Willis and NFP, using its “playbook” for alleged employee poaching. Aon’s lawsuit cites many other lawsuits against Alliant from brokers.

In this latest suit, Aon similarly refers to Alliant’s “playbook,” adding that it now has a new chapter to acquire talent from the competition to start an entirely new line of business.

“Alliant has a history, pattern and practice of targeting Aon, specifically,” according to the lawsuit. “For over a decade, Alliant engaged in multiple raids on Aon’s officers, employees and clients.”

Aon seeks preliminary and permanent injunctions against Alliant, and the return of property.

In the statement to IJ, Alliant’s Peter Arkley, president, retail property & casualty of Alliant Insurance Services, said, “While it may not please our competitors, Alliant is changing the way our clients approach risk management and benefits. Alliant is thrilled to welcome our new talented reinsurance professionals to Alliant Re.”

Alliant said its competitors, including Aon, have sought to suppress employee mobility through the excessive use of litigation, and in the two cases between Alliant and Aon that have gone to trial, Alliant has prevailed. Both were in California Superior Court.

Alliant said it has strict rules regarding the return of property and equipment to former employers and the use or disclosure of proprietary information. “Alliant instructs prospective employees to act solely on behalf of their current employer until they resign,” the insurer said.

The case is Aon plc, et al v. Alliant Insurance Services, Inc., et al, 1:23-cv-03044, U.S. District Court, Northern District of Illinois.