The actress starred alongside Robert Downey Jr, Chris Hemsworth, Chris Evans, Jeremy Renner, and Mark Ruffalo in the recent Marvel blockbuster. The film has grossed over $1 billion to date, making it the third biggest-selling movie in history.
A source has told The Sun that movie bosses are keen to have Johansson return as Russian spy Natasha Romanoff, and are prepared to make her the highest paid actress in Hollywood with the $20 million fee.
"Scarlett is the hottest star in Hollywood and her inclusion in the sequel is a must," the source explains.
"Producers think that as the only lead woman in the film, male fans have found her a key ingredient - both for sex and story appeal. She is loved by critics too."
The source has also revealed that filming on the highly anticipated film is expected to begin next year.
"Everyone is confident that [Scarlett will] sign and be ready for 2013 filming," the insider added.
Hemsworth, Renner and Downey Jr will also apparently be receiving 50% pay rises.
Watch a clip from The Avengers below: