Nine years to the day since Andrew Sandler co-founded financial services powerhouse Buckley Sandler, he will retire from the firm.

In a letter to colleagues sent Wednesday morning, Sandler wrote that after returning from a “wonderful family trip … I have reached the conclusion that it has become too difficult to continue to juggle my role as chairman and executive partner of Buckley Sandler with my responsibilities leading Treliant Risk Advisors, Temerity Capital and Asurity Technologies and still have time to pursue my personal interests.”

His last day at Buckley Sandler, which had profits per partner of $2.6 million in 2016, will be March 20.

Buckley Sandler was founded in 2009 when Sandler, who led the consumer financial services enforcement and litigation practice at Skadden, Arps, Slate, Meagher & Flom, joined forces with D.C. boutique Buckley Kolar.

Today, the 158-lawyer firm represents 21 of the 25 largest banks in the United States as well as the top 10 credit card issuers. It opened its sixth office, in San Francisco, in January and also recently landed Tina Tchen to lead its Chicago office. The former chief of staff to First Lady Michelle Obama is spearheading the Time's Up Legal Defense Fund.

In an interview, Sandler said stepping away from the firm he helped build is difficult. “I'm only comfortable doing this now because we have from Day One worked hard at institutionalizing the firm in terms of diversity of clients, business development and a strong, comprehensive leadership team,” he said.

The firm will retain the name Buckley Sandler, and while no one will replace Sandler in the role of chairman, Benjamin Klubes and John Kromer will continue to serve as co-managing partners. Christopher Witeck has been appointed as deputy managing partner, and Clint Rockwell and Jonice Gray Tucker have been added to the executive committee.

“We're optimistic about 2018 as our momentum continues in our white-collar and government enforcement practices, we leverage technology to enhance firm licensing, e-discovery and regulatory capabilities,” Klubes said. He also touted the firm's workplace cultural compliance, anti-money laundering, state attorneys general, and banking practices, as well as fintech-related work.

Although Sandler will no longer be active at the firm, he'll be far from idle. He'll continue to  serve as CEO of financial services industry consulting firm Treliant, which was founded in 2009. Buckley Sandler was originally an investor, but Sandler bought the firm out several years ago.

 He is also chairman of compliance software provider Asurity, established in 2015, and he founded private investment company Temerity in 2014. Both are independent entities from Buckley Sandler.