After 17 years at Simpson Thacher & Bartlett, helping the firm build out its presence in Los Angeles, litigator Deborah Stein has left the East Coast-based firm to join Gibson, Dunn & Crutcher.

Stein joined Gibson Dunn on Thursday as a partner in the Los Angeles office, where she will continue to represent insurers and other clients in commercial litigation.

“It wasn't an easy decision. Simpson Thacher was my home for nearly two decades,” Stein said. “But, no one has a litigation department that rivals Gibson Dunn's and that was really at the heart of my reason for leaving.”

Stein started her career at Simpson Thacher in 2001, right after her clerkship for U.S. District Judge Peter C. Dorsey in Connecticut. A bit more than a year into her time at the New York firm, she was relocated to Los Angeles to help grow the office's then-nascent insurance practice.

“It became increasingly important to be at a firm with a very strong commitment to Los Angeles and California,” Stein added. Her move to Gibson Dunn was brokered by Larry Watanabe and Ken Schwartz of Watanabe Nason.

Over the years, Stein's practice has evolved to include cybersecurity and trade secrets litigation, securities and consumer class actions, and insurance coverage and business practices disputes. She also advises clients on False Claims Act matters and whistleblower allegations.

The Travelers Companies Inc. and National Liability & Fire Ins. Co. are among her recent clients, according to court records.

“Deb brings impressive litigation skills and substantial trial experience that will add further depth to our existing group of first-chair litigators in the Los Angeles office,” Jay Srinivasan, co-partner in charge of the Los Angeles and Century City offices, said in a statement.  “She is also active in the legal and business communities, enjoying a high profile in both. It is not often that someone like Deb becomes available and we are lucky to have her.”

In the Los Angeles legal community, Stein serves on the board of directors of Public Counsel, the board of governors of the Women Lawyers Association of Los Angeles and the global advisory board of the Women in Law Empowerment Forum.

Simpson Thacher did not respond to a request for comment regarding Stein's departure.