According to Caughtoffside, the deal is almost complete.
Manchester United's contract with Ronaldo is valid until June 2023.
The club finished sixth in the Premier League last season and will not qualify for the 2022/23 Champions League.
Manchester United are 14th in the Premier League this season with three points.
On August 25, former France striker Djibril Cisse called on Ronaldo to move from Manchester United to Marseille.
Earlier, Manchester United midfielder Casemiro spoke about his teammates Ronaldo and Rafael Varane.