McLaren CEO Zak Brown sent a formal letter to FIA President Mohammed Ben Sulayem last week requesting rule changes that would restrict multi-team ownership in Formula One, according to people familiar with the correspondence. The timing is deliberate: Mercedes is actively exploring minority investment positions in at least two rival teams, while Red Bull continues operating both its primary squad and its junior outfit, AlphaTauri, under common ownership by Red Bull GmbH.

Brown's letter argues that shared ownership creates structural conflicts around technical collaboration, driver development, and strategic race decisions that cannot be resolved through existing separation protocols. He cited specific incidents from the 2023 season where AlphaTauri's pit strategy appeared coordinated with Red Bull's championship battle, though he stopped short of alleging rule violations. The letter also flags Mercedes' reported interest in 10-15% stakes in McLaren's closest midfield competitors as a governance problem that will only compound as team valuations continue rising. Current regulations permit multi-team ownership provided teams maintain separate technical operations and do not share intellectual property, but Brown's position is that commercial incentives make true separation impossible.

The financial stakes explain the urgency. F1 team valuations have climbed 40% since 2021, with midfield constructors now trading at $800M-$1.2B based on recent minority transaction comparables. Mercedes' parent company Daimler has publicly stated its intent to diversify revenue beyond its factory team, and minority stakes in rivals offer a hedge if new engine regulations in 2026 compress performance differentials. For McLaren, which took Ares Management capital at a $1.4B valuation in 2022, any Mercedes investment in a competitor like Alpine or Williams would mean sharing the grid with a manufacturer that supplies engines to four teams and holds equity in two. Brown's letter argues this concentration gives Mercedes disproportionate influence over sporting outcomes, sponsor negotiations, and technical rule-making.

The FIA's response will set precedent for how Formula One treats ownership consolidation as the sport's commercial growth attracts non-traditional investors. Ben Sulayem has said privately he views multi-team ownership as a commercial matter for Formula One Management, not a sporting matter for the FIA, according to two paddock sources. That position creates a gap: FOM has financial incentives to allow transactions that increase liquidity and attract capital, while the FIA's remit is competitive balance. Brown's letter attempts to force the issue by framing it as a sporting integrity question that requires FIA governance, not commercial flexibility.

Watch for Brown to raise the issue again at the next F1 Commission meeting in April, where rule changes require 70% support from teams and the FIA. Mercedes principal Toto Wolff is expected to argue that minority stakes without operational control fall outside existing restrictions, setting up a direct clash with McLaren. Separately, monitor whether Red Bull announces structural changes to AlphaTauri's ownership ahead of the season opener, a move that would defuse criticism without conceding Brown's larger point.

By the time teams arrive in Bahrain for pre-season testing in late February, the ownership question will either be resolved through quiet compromise or escalate into the first governance crisis of the new Concorde Agreement cycle. Brown filed the letter the same week McLaren announced a $300M paddock hospitality expansion, signaling he plans to keep raising the issue whether or not the FIA acts.