Dozens of Wells Fargo Insurance employees in San Francisco and San Carlos have defected to join a newly formed ABD Insurance and Financial Professionals, reclaiming the name and perhaps the culture of an influential brokerage that was acquired by Wells Fargo Insurance Services back in 2007.

Before being acquired, ABD had a significant presence in the North Bay, with a good deal of the area's insurance brain trust coming out of the brokerage. Subsequently, top North Bay insurance executives landed at Woodruff & Sawyer in Novato, two joined EPIC to start a Petaluma branch and other longtime North Bay professionals remained with Wells Fargo.

While the shifting employees -- said to range between 50 and 75 people -- are in the South Bay and in San Francisco, the move to inject another large brokerage into the landscape has implications throughout the Bay Area and had North Bay brokers abuzz with curiosity and speculation.

Meanwhile, Wells Fargo isn't going down without a fight -- it filed a lawsuit alleging trademark infringement, false advertising and unfair competition in U.S. District Court in San Francisco recently, with the intent of stopping ABD from using the name.

"We definitely feel we have a strong case," Wells Fargo spokeswoman Katie Ellis said.

The new ABD is being headed by Brian Hetherington, a former Wells Fargo executive who came with the original acquisition, and co-founders Kurt de Grosz and Eric Alburger, who are sons of two founding partners from the original Alburger Basso de Grosz company.

Mr. de Grosz had noticed the ABD trademark expired in October 2011, according to Mr. Hetherington, who left Wells Fargo in January of this year.

"So the genesis of ABD started then," he said.

Mr. Hetherington said he and his ABD co-founders were in negotiations with Wells Fargo about purchasing a portion of the business but, he said, Wells Fargo discontinued talks.

Despite the lawsuit, Mr. Hetherington said he had nothing but respect for his former employer.

"We have the utmost respect for Wells Fargo," Mr. Hetherington said. "But we have an opportunity to build a great business. The people who appreciate the boutique companies are going to look to us. We are more of a boutique. The big bank is not for everyone."

Wells Fargo said the number of employees who defected from San Carlos and San Francisco is "more than 50 but not as much as 70."

"Staff changes are a normal course of business," said Ms. Ellis, also noting that Wells appointed a new Bay Area head of operations, Bob Volkel.

ABD officially began business on July 19.

"We had to scramble," Mr. Hetherington said, adding that ABD will operate offices in Redwood City, San Francisco, San Mateo and San Jose and has 110 employees already.

In the lawsuit, Wells Fargo says: "Rather than establish a brand and reputation of their own, the defendants are attempting to misappropriate the goodwill of a recognized brand and compete in a manner calculated to deceive consumers and irreparably harm Wells Fargo."

Mr. Hetherington said ABD expected the lawsuit to be a "minor distraction."

The ABD Insurance Services name was officially born in 1990 from the merger of two Bay Area brokerages, Alburger Basso de Grosz Insurance Services of Belmont and Mario L. Basso Agency of San Mateo, along with investment from Transamerica Insurance Group

In 1993, the company acquired Ellingson & Jones Insurance Services of Santa Rosa, whose founder, Sam Jones, was president and chief executive officer of ABD and later served as executive vice president and West region manager for Wells Fargo until retiring several years ago.

Other acquisitions followed, including Willis Corroon Group of Sacramento and Petaluma-based Metzger & Wilkey Inc., both in 1996.

In 2000, ABD further increased its North Bay presence, assuming a then 20-year Sonoma County agency veteran, Dranginis & Associates, run by Michael Dranginis. Another acquisition was completed in summer 2008, when ABD took on the expertise of Santa Rosa-based Martin Financial/Insurance Services.

So could the resurrected ABD return to the North Bay again?

"We're going to take our time and make sure we have the right people," Mr. Hetherington said. "If we do this right, we'll grow our business in the North Bay, the East Bay and maybe  Sacramento."

This article has been clarified to note that ABD was in negotiations about purchasing the business, not the ABD name, from Wells Fargo.