Formula 1 is expected to approve grid expansion for an 11th team originally started by Michael Andretti as early as next week.

The race team will be called Cadillac F1 and powered by Ferrari engines when it enters the sport in 2026.

General Motors are expected to complete their own Cadillac power unit ahead of the 2028 season.

Multiple industry insiders spoke to the Associated Press about the grid expansion on condition of anonymity because an announcement ahead of next Saturday's Las Vegas Grand Prix could potentially steal the spotlight from the showcase event on the F1 calendar.

The delayed decision to expand the grid for the Andretti-started entry is a reversal for F1, which initially denied the application despite approval from sanctioning body FIA.

The existing 10 teams, who have no voice in the matter, have largely opposed expansion because of the dilution in prize money.

The teams also contended that Andretti should buy a team rather than expanding the grid.

No teams have marketed themselves for sale, however, and Andretti in 2020 already tried to close a deal that would have taken over the existing Sauber team.

The Las Vegas race marks the third and final stop this year for F1 in the United States, where the series has exploded in popularity over the last five years.

The three US has three races - Miami; Austin, Texas and Las Vegas - more than any other country.