A New York federal court issued a preliminary injunction barring California-based insurance broker Alliant and two employees from soliciting and accepting the workers' former Marsh & McLennan Agency clients, yet refused to prevent their continued servicing of clients who have already moved their business to Alliant.

In an order Monday, U.S. District Judge Ronnie Abrams concluded that Marsh is entitled to limited injunctive relief against Alliant Insurance Services Inc. and employees Andrew Oldenburg and Elizabeth McKinney, but not as to two additional employees, Kimberly Moore and Danielle Black.

The judge also denied as moot Marsh's application for a temporary restraining order and denied without prejudice Marsh's bid for expedited discovery, saying the broker has neither demonstrated how its ongoing harm justifies the need for expedited discovery nor identified the specific discovery it seeks.

According to court filings, Oldenburg previously worked for and owned a portion of Montana-based insurance broker PayneWest, which Marsh acquired in April 2021. As part of the purchase, Oldenburg agreed to work for Marsh and to sell his PayneWest shares to the broker. He also signed a restrictive covenant agreement in effect through April 1, 2026, which included provisions limiting his professional activities if he were to leave Marsh.

Oldenburg's client service team, including McKinney, Moore and Black, also moved from PayneWest to Marsh, court documents stated. All four employees signed nonsolicitation agreements restricting their ability to solicit and serve Marsh clients and employees.

In July, Oldenburg resigned from Marsh and filed a suit in Oregon state court, seeking to have the provisions of his RCA and NSA declared unenforceable. McKinney, Moore and Black also resigned from Marsh, and within days, all four had joined Alliant, according to court filings.

Following the departures, a number of the employees' former Marsh clients began to transition their business to Alliant, according to court documents.

Marsh filed the present action in August, accusing the former employees of breaching the respective agreements they signed when joining Marsh. The broker also accused Alliant of aiding and abetting Oldenburg's alleged breach of the duty of loyalty, and improperly interfering with Marsh's business relations and its contracts with the former employees.

Judge Abrams held Monday that Marsh is entitled to limited injunctive relief against Alliant, Oldenburg and McKinney because it has demonstrated that it is likely to succeed on the merits of at least some of its claims against those defendants.

First, the judge said, Marsh has shown that Oldenburg and McKinney have breached the express terms of the NSAs by soliciting, accepting, and servicing former Marsh clients at Alliant. However, Marsh has not yet demonstrated that Moore or Black are also engaged in servicing or soliciting their former Marsh clients at Alliant, the judge said.

Judge Abrams further held that the NSAs are enforceable under New York law.

As for the RCA, the judge found that the agreement's "restrictions on Oldenburg's solicitation of prospective clients are overbroad, unreasonable and unenforceable." While a portion of the RCA is unenforceable, Judge Abrams held that partial enforcement of the agreement's valid provisions, including restrictions on PayneWest clients, is appropriate.

With respect to Marsh's tortious interference of contract claim, the judge found that the broker has not yet provided evidence that Alliant had actual knowledge of the agreements' terms. However, Judge Abrams said, Marsh has met its burden of establishing that there is a strong likelihood that it will eventually be able to prove Alliant's knowledge of the agreements.

Marsh has also shown that it's likely to suffer irreparable harm, in the form of the loss of client relationships and customer goodwill, without an injunction barring Alliant from accepting former Marsh clients in violation of the RCA and NSAs, Judge Abrams held.

However, an injunction barring Alliant and the employees from continuing to service former Marsh clients that they already solicited and accepted would not remedy Marsh's alleged harm, the judge said.

"The balance of the equities and the public interest both favor the limited preliminary injunction imposed in this order," Judge Abrams added.

Representatives of the parties did not immediately respond to requests for comment Tuesday.

Marsh is represented by David W. Garland and A. Millie Warner of Epstein Becker Green.

Alliant and the employees are represented by Timothy J. Stephens, Karen P. Pohlmann, Cassidy D. Britt and Peter M. Fay of Morgan Lewis & Bockius LLP.

The case is Marsh & McLennan Agency LLC v. Alliant Insurance Services Inc. et al., case number 1:25-cv-06936, in the U.S. District Court for the Southern District of New York.