The FIA has received several entry requests to expand the grid beyond the current 10 teams.
Michael Andretti's high-profile bid is believed to be close to being approved by the governing body. But Andretti is still facing fierce resistance from F1, which will also have to approve any entry, and the majority of the teams due to concerns over their prize fund being diluted.
Speaking to Motorsport.com and Autosport's sister website Motorsport-Total, McLaren chief Brown believes that, provided the current $200m anti-dilution fee is at least tripled in the next Concorde Agreement from 2026, a viable expansion team could be financially beneficial for the existing outfits.
When asked why he would support an 11th team diluting the prize money, Brown replied: "Because I believe I'm not giving up that money.
"It has to be the right team with the right resources. Let's assume for a moment it is. If they pay the right franchise fee - which is not 200 million, let's say it's 700 million - then I get 70 million.
"The dilution of an 11th team is about 10 million a year. So, if I get 70, it will be covering me for seven years.
"Then if it costs 700 just to enter, it's created 700 million more in franchise value. So, whatever I'm worth today, pick a number... two billion, now I'm worth 2.7 billion.
He added: "Also, if you have an 11th team, the scarcity is even greater because there's only room for 12 teams. As soon as there's 12, now you're sold out, so that drives the demand up."
IndyCar stalwart Andretti, who has rebranded his worldwide racing organisation to Andretti Global, tapped up American OEM General Motors for his F1 programme, although it is yet to become clear just how involved GM would be.
But Brown pointed out that even if GM were just to treat F1 as a branding exercise, some of the marketing money it spends in the series would also trickle down to the teams.
"The teams get 70% of the money that comes into the sport. If General Motors comes in and they spend circuit advertising, sponsor a race, let's say they spend some Paddock Club, they spend 100 million a year, we get 70 of that," he explained.
"So, all of a sudden, the 100 that they're taking out of the system, they're putting 70 of it back or 50 of it back. And then at the right franchise number, I'm not getting diluted.
"I don't know enough about Andretti's bid to have a view on whether they should or shouldn't [be accepted]. No one's seen the bid.
"But if someone's prepared to pay the right franchise fee, it's a quality racing team, we know who they are and where their money is from and they're bringing an OEM and they're paying the right fee, then I don't see it as diluting. I see it as additive."
