The 36-year-old Australian actress and producer is part of the core creative team negotiating over a second Barbie film alongside director and co-writer Greta Gerwig, co-writer Noah Baumbach and Ken star Ryan Gosling.
Variety has now reported Warner Bros has made more than six offers over the past three years for a follow-up to the crowdpleaser, but the publication has stated no agreement has been reached – leaving the future of the studio's highest-grossing film apparently uncertain.
One studio source described the latest proposal as "life-changing money", telling Variety it represented the largest offer Warner Bros had made to a filmmaking team and its stars. Another deal source disputed the description, saying the combined cost of hiring all four might be historic but their individual compensation was not.
The negotiations follow the extraordinary success of Barbie, which became a global cultural phenomenon after its 2023 release and grossed more than $US1.4 billion ($A2 billion) worldwide.
Robbie starred as the title character and produced the film through LuckyChap Entertainment, while Gerwig directed from a screenplay she wrote with Noah.
Gosling's performance as Ken earned him an Oscar nomination.
None of the four central creatives were contractually obliged to make a sequel under their original deals, according to the Variety report.
Gerwig was not tied to another film when she agreed to direct Barbie, meaning Warner Bros has had to negotiate fresh contracts following the movie's enormous commercial success.
The new financial demands reportedly involve increases in upfront fees and back-end participation. Gosling is said to be seeking $US20 million ($A28 million) to return as Ken, while Robbie was initially projected to earn about $US50 million ($A71 million) in salary and back-end payments from Barbie.
A studio source told Variety her eventual compensation from the original film would finish "well ahead" of that figure.
One source said the team was satisfied with the upfront salaries being offered but remained unhappy with the back-end terms, although another source disputed both claims.
Variety reported the group is not seeking first-dollar gross participation.
Robbie is also moving ahead with another Warner Bros project – an Ocean's 11 prequel alongside Bradley Cooper.
The contractual deadlock also has implications for Mattel, whose Barbie doll provided the intellectual property behind the film.
According to Variety, Warner Bros has a limited period in which to put another Barbie movie into active development before relevant rights revert to Mattel, potentially forcing the toy company to pursue a reboot rather than building directly on Gerwig's film.
Gerwig and Baumbach have an idea for a sequel, according to two sources cited by Variety, but are reportedly unwilling to reveal it until agreements have been signed.
Representatives for the filmmakers, actors, Warner Bros, Mattel and CAA declined to comment to Variety.
