Alan Levin’s tenure atop Barnes & Thornburg is drawing to an end.

The Indianapolis-based Am Law 100 firm announced Wednesday that Levin will step aside as managing partner as of Nov. 1 and make way for successor Robert Grand.

Levin, 59, was elected to the top leadership role in 1997. In the 17 years since, Barnes & Thornburg’s management committee has reelected him to six three-year terms—most recently in December 2012—as the firm grew into a 522-lawyer shop with 12 offices spread across the U.S.

Barnes & Thornburg has been Levin’s sole professional home. On his first day as an associate at what was then Barnes, Hickam, Pantzer & Boyd in 1982, the Indianapolis-based firm merged with South Bend, Ind.-based Thornburg McGill Deahl Harman Carey & Murray.

“I got to experience a [law firm] merger well before mergers were becoming the popular thing,” jokes Levin. “But over the years we’ve tried to tried to focus on growing laterally instead.”

Indeed, outside of absorbing a few small IP boutiques and picking up the 22-lawyer Parsinen Law Firm in Minneapolis in 2009, Barnes & Thornburg has resisted the urge to enter into any substantial mergers.

As Barnes & Thornburg followed that course, Indianapolis-based Baker & Daniels combined with Minneapolis-based Faegre & Benson to form Am Law 100 firm Faegre Baker Daniels on Jan. 1, 2012, and regional rivals such as Ice Miller and Bingham McHale pursued tie-ups of their own.

“We’ve certainly had discussions with other firms, but nothing that ever got too serious,” Levin says. “You always have to listen, but we pride ourselves on our democratic nature. We’re not going to do something like that unless an overwhelming majority of our partners support it.”

Levin, a corporate lawyer by training, mostly gave up his practice while guiding Barnes & Thornburg’s operations. He says that succession planning with the firm’s management committee began about six months ago, and that Grand, a member of the 20-person committee, emerged as the most logical candidate to succeed him as managing partner.

It’s not the first time Grand, 58, has followed Levin’s lead. He previously took over as the head of Barnes & Thornburg’s home office in Indianapolis after Levin vacated the post 17 years ago. A former chief-of-staff to late Indiana Gov. Robert Orr, Grand joined the firm in 1987 and has become a prominent Republican political powerbroker in the Hoosier State.

During the 2012 presidential election, Grand served as a key campaign bundler for Mitt Romney, and the Barnes & Thornburg leader-to-be maintains a robust roster of lobbying clients, according to U.S. Senate records. The firm itself has taken in $1 million in lobbying revenue through the first quarter of this year, according to data compiled by the Center for Responsive Politics.

While acknowledging that Grand’s new administrative duties will most likely require him to make some adjustments to his practice, Levin says that his chairman emeritus role will allow him to assist with the leadership transition. Levin adds that under the terms of Barnes & Thornburg’s partnership agreement, the remaining two years of his term as managing partner will be filled by Grand.

Asked about his greatest challenges managing a large firm during a turbulent time in the U.S. market for high-end legal services, Levin says that advances in technology and the shift from hourly billing to alternative fee structures are among the most significant changes to occur on his watch.

Barnes & Thornburg had a productive 2013 as the firm’s gross revenue jumped nearly 12 percent, to $344 million, while profits per partner rose another 8.2 percent, to $855,000, according to The American Lawyer’s most recent financial reporting.

Levin says the firm remains focused on expanding its operations in Atlanta, Columbus and Los Angeles—three cities in which Barnes & Thornburg has opened offices in recent years. The Los Angeles outpost in particular has grown rapidly from a half-dozen lawyers in 2011 to roughly 30 today, says Levin, adding that his firm has hired two partners in the city already this year from Akin Gump Strauss Hauer & Feld.

While a reliance on lateral hires can be a risky strategy for achieving growth, Levin says that Barnes & Thornburg is careful to choose attorneys who match its traditional midwestern firm culture and are able to bill clients at rates well below those charged by the firm’s competitors on both coasts.

“Now more than half of our lawyers have come from outside the firm,” Levin says. “So of course our culture has evolved. And when you’re recruiting others, you also have to remember to tend to your own house so your people believe they’re being treated in a fair manner.”

Among the firm’s key hires last year were former Dickstein Shapiro counsel and insurance coverage IP practice head and cybersecurity coverage cohead Scott Godes, who joined the firm as a partner in Washington, D.C., a Beltway-based government contracts group poached from Greenberg Traurig, product liability partner Alexander Calfo from his own firm in Los Angeles and Bingham Greenebaum Doll labor and employment chair Jeffery Mallamad in Indianapolis.

While it experienced relatively few lateral departures in 2013, Barnes & Thornburg did see Peter Reyes Jr.—a former in-house IP counsel at Wayzata, Minn.-based agribusiness giant Cargill who came aboard in Minneapolis just last year—leave earlier this year after being nominated to fill a vacant seat on the Minnesota Court of Appeals.