(Reuters) - A Chicago firm launched by a group of Big Law vets a year and a half ago has brought on a former advisor and legal counsel to Mayor Lori Lightfoot who helped negotiate an end to the city's 14-day public schools strike in 2019.

Michael Frisch will lead Croke Fairchild Morgan & Beres' government litigation and investigations practice. Like his new colleagues, Frisch has a Big Law background: He worked at Mayer Brown for seven years before joining the Commodity Futures Trading Commission in 2015.

His tenure at Mayer Brown led to his gig for the city of Chicago – Lightfoot, a partner at the firm, was his friend and mentor. He worked on her mayoral campaign and the transition in 2019.

Frisch joined Lightfoot's office as a senior advisor and legal counsel, where he oversaw all major collective bargaining and led the legal aspects of the city's response to the COVID-19 pandemic, until his departure earlier this month.

"I thought long and hard about going back to a bigger firm," Frisch said about his decision to join CFMB. "I was really attracted to what they're trying to build here. Something that was growing and thriving, and a place I could be entrepreneurial, a place that was flexible."

Drew Beres, one of the firm's founding partners, said Frisch has been a friend for more than a decade.

CFMB launched in December 2019 with eight attorneys, including four founding partners who previously worked at Kirkland & Ellis, Michael Best & Friedrich, Schiff Hardin and Sidley Austin. It has offices in Chicago, Milwaukee and Lake Forest, Illinois.

Since then, the firm has quadrupled in size. With two more partners joining the firm in May, CFMB will have 34 attorneys and 38 employees altogether, Beres said.

The firm has also bolstered its political bona fides – in February, it welcomed Lisa Duarte, the former first assistant deputy governor for budget and economy under Illinois Governor J.B. Pritzker, as the leader of its government affairs and public law practice.

Beres declined to say what kind of matters Frisch will be handling, but the firm is hiring attorneys who can handle government litigation and investigations.

"He came in with a full plate, that we had stuff ready for him knowing he was coming that required his talents and had to be done by him," Beres said. "We need more people."