McLaren CEO Zak Brown sent a formal letter to FIA President Mohammed Ben Sulayem calling for regulatory changes that would prohibit common ownership structures across multiple Formula 1 teams. The letter, confirmed by Reuters on April 22, arrives as the 10-team grid faces renewed expansion pressure and $1.2 billion Audi completes its Sauber stake acquisition.

Brown's communication does not cite a specific target but the timing is pointed. Audi finalized its Sauber takeover in March, creating the grid's first major OEM-backed ownership shift since Renault sold Alpine's parent structure in 2021. Andretti Global, still circling after FIA approval but commercial rejection in January, has floated partnership models that could involve existing team investors. Brown's letter effectively seeks to close structural doors before they open.

The regulatory gap matters because F1's Concorde Agreement prohibits direct team ownership overlap but remains silent on holding-company architectures, shared investor syndicates, or phased stake transfers. Liberty Media itself owns the commercial rights while maintaining arm's-length governance, a structure teams accepted in 2017 but now view with suspicion as valuations approach $2 billion per entry and private equity circles. Brown's move is less about Audi—whose full takeover is clean—than about preventing a future where a sovereign fund, family office, or consortium holds minority stakes in two teams while claiming independence.

For team operators, the letter introduces pre-emptive uncertainty. McLaren sits in third place in the Constructors' Championship with $216 million in reported 2025 revenue from sponsorship, a figure that depends on competitive separation. If a major investor someday holds 15% of McLaren and 20% of Williams, sponsor exclusivity clauses face immediate legal review. Kit partners, especially, negotiate on the premise that team rivalries are uncompromised. The cigarette and alcohol categories learned this the hard way when tobacco money flowed to four teams simultaneously in the 1990s; conflict-of-interest clauses now appear in 80% of Tier 1 sponsorship contracts.

Brown's leverage is structural. He chairs the F1 Commission alongside nine other team principals, and ownership rules require 70% team approval plus FIA and Liberty consent. That threshold is reachable if Brown frames the change as competitive-integrity housekeeping rather than Andretti-blocking. The FIA, meanwhile, faces its own governance scrutiny after Mohammed Ben Sulayem's public clash with Liberty Media over the Las Vegas Grand Prix financials. A quiet rule tightening lets the FIA show decisiveness without antagonizing the commercial rights holder.

The political timing also aligns with 2026 power-unit regulations, which reset cost structures and create natural leverage points for governance changes. Teams are already negotiating updates to the Concorde Agreement's revenue-share formula, which currently allocates 63.5% of F1's commercial income to the grid. Any ownership-rule revision would likely fold into that broader negotiation, giving Brown a second bite: tighter ownership limits in exchange for, say, a 0.5% bump in McLaren's historical bonus payments.

What to watch: FIA's response timeline, which historically runs 60-90 days for rule-change proposals. Team principals meet in Monaco on May 23; ownership structure is expected on the agenda. Andretti's next public move, likely before the Canadian Grand Prix in June, when U.S. media pressure peaks. Any Concorde Amendment language floated before the summer break in August, when lawyers traditionally pre-negotiate ahead of October's formal signings.

Brown did not copy the letter to Stefano Domenicali, Liberty Media's F1 CEO, but Domenicali's office confirmed receipt within 48 hours—a courtesy that suggests prior alignment or at minimum no surprise.