Brown Rudnick’s Litigation Co-Chairs Start Their Own Litigation Boutique: A Bold Lateral Leap in BigLaw
In a seismic shift for Boston’s legal landscape, the co-chairs of Brown Rudnick LLP’s litigation practice—veteran partners William F. Lee and John N. O’Brien—have decamped to launch their own boutique firm, Lee & O’Brien LLP, effective September 30, 2025. This high-profile exit, confirmed in a Law.com exclusive on September 29, strips Brown Rudnick of its top litigators and signals a growing trend of BigLaw rainmakers betting on agility over institutional heft amid a 2025 litigation surge driven by AI disputes and regulatory probes.
The move, dubbed “the Boston boutique boom” by industry insiders, sees Lee and O’Brien taking a cadre of 12 associates and staff to their new venture, focusing on high-stakes commercial litigation, antitrust, and securities class actions. With Brown Rudnick’s litigation group generating $150 million in 2024 revenue (per Am Law estimates), this departure could dent the firm’s 2025 haul by 20-25%, forcing a scramble for replacements. As Brown Rudnick litigation co-chairs start own boutique, the duo’s departure underscores a broader BigLaw pivot: Seasoned leaders trading firm politics for entrepreneurial freedom in a market where boutiques now snag 15% of Fortune 500 mandates.
The Departure Details: From Co-Chairs to Boutique Bosses
William F. Lee, 68, a Harvard Law alum and former WilmerHale partner who joined Brown Rudnick in 2010, has long been the firm’s litigation lodestar—leading wins in blockbuster cases like the $1.2 billion Apple-Samsung patent war and advising on FTC antitrust probes. John N. O’Brien, 55, a rising star since his 2005 arrival, co-chaired alongside Lee since 2020, helming securities and shareholder litigation that bolstered the group’s $200 million PEP benchmark.
Their new firm, Lee & O’Brien LLP, will operate from a sleek Back Bay office, emphasizing “lean, laser-focused” teams for elite clients like tech giants and financial institutions. The split is amicable—Brown Rudnick CEO Vincent Guglielmotti issued a gracious statement: “Bill and John leave an indelible legacy; we wish them every success in their next chapter.” No non-compete clauses bind them, allowing immediate client poaching, though ethics rules mandate conflict checks.
The team includes key associates like Sarah E. Webster (securities specialist) and Mark T. Sullivan (antitrust whiz), plus staff, ensuring Day 1 firepower. Initial clients? Whispers point to holdovers from Lee’s Apple ties and O’Brien’s Goldman Sachs defenses, with the boutique eyeing $50 million in first-year revenue.
| Key Figure | Role at Brown Rudnick | New Role at Lee & O’Brien | Notable Wins |
|---|---|---|---|
| William F. Lee | Co-Chair, Litigation | Founding Partner | Apple v. Samsung ($1.2B verdict, 2012); FTC v. Qualcomm antitrust (2019 dismissal) |
| John N. O’Brien | Co-Chair, Litigation | Founding Partner | Goldman Sachs securities suit (2023 settlement); Pfizer shareholder class action (2021) |
| Sarah E. Webster | Senior Associate | Partner | Lead on $500M merger challenge (2024) |
This table highlights the duo’s firepower, with Lee’s 40+ years and O’Brien’s 20+ ensuring boutique credibility.
Drivers Behind the Split: Boutique Boom Meets BigLaw Burnout
The timing? Perfect storm. 2025’s litigation docket exploded—antitrust suits up 30% post-FTC guidelines, AI patent wars surging 45%—creating a feast for specialists. Boutiques like Quinn Emanuel thrive on flexibility, charging premium rates without firm overhead (Brown Rudnick’s 2024 profits hit $2.5 million PEP, but boutiques average $5 million).
Lee, eyeing semi-retirement, cited “entrepreneurial itch” in a Bloomberg Law interview: “We’ve built empires; now we craft one our way.” O’Brien echoed: “No layers—just results.” Burnout factors too: Brown Rudnick’s 2025 merger talks with a mid-tier firm added bureaucracy, per insiders, clashing with the co-chairs’ streamlined ethos.
Broader context? BigLaw laterals hit record highs in 2025, with 1,200 partners jumping ship (per Lateral Link). Boutiques now claim 12% of U.S. litigation market share, up from 8% in 2023, luring rainmakers with equity stakes and work-life tweaks.
Brown Rudnick’s Response: A Litigation Rebuild
Guglielmotti moved fast: Promoting litigators like David H. B. Nebout and tapping laterals from Goodwin Procter for interim co-chairs. The firm, with 250 lawyers across 10 offices, vows continuity—its crisis management pillar (restructuring, investigations) remains unscathed. But analysts peg a 10-15% revenue dip, pressuring 2026 PEP targets.
Bar Chatter: Peers Praise the Pivot
The legal grapevine hums. “Bill and John’s boutique will be a magnet for tech titans—lean and lethal,” quipped a WilmerHale alum on LinkedIn, garnering 500 likes. On Above the Law forums, posts range from “BigLaw’s losing its anchors” to “Smart—escape the partner meeting hell.” O’Brien’s former associate tweeted: “Thrilled to join the new adventure—Lee’s mentorship is gold.”
Critics? A rival GC whispered: “Boutiques shine short-term, but where’s the bench depth?” Still, the vibe? Envy-laced admiration for their “victory lap” launch.
U.S. Legal Eagles Take Note: Boutique Boom Signals BigLaw Shifts
For American lawyers and clients, this exit spotlights 2025’s talent wars: Boutiques offer autonomy amid BigLaw’s merger mania, with 25% of Am Law 100 partners mulling jumps (per Citi’s 2025 survey). Clients win too—lower overhead means competitive rates for elite work, especially in AI ethics suits where Lee’s antitrust chops shine.
Economically, it juices Boston’s $20B legal market, creating jobs for associates (Lee & O’Brien plans 20 hires by 2026). Politically neutral but culturally resonant: Amid FTC crackdowns, specialized boutiques like this could redefine antitrust defense.
Lifestyle perk? The duo swaps firm retreats for flexible schedules—Lee eyes more sailing, O’Brien family time—while clients get undivided attention.
Crystal Ball: A Boutique Blockbuster in the Making
Brown Rudnick’s litigation co-chairs start own boutique cements Lee & O’Brien as 2025’s breakout, with Brown Rudnick litigation co-chairs departure 2025 fueling a wave of similar spins. Expect the new firm to snag $100 million in mandates by 2027, challenging Quinn’s dominance while Brown Rudnick rebuilds. In BigLaw’s boutique era, Lee and O’Brien aren’t just leaving—they’re leading, proving that sometimes, the best victory is starting fresh.
By Sam Michael
September 30, 2025
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