The details of the offer, previously unreported, come as Mark Zuckerberg’s tech and social media giant that also controls Facebook, looks to appease increasingly tough EU regulators ​that are tightening the screws on Big Tech.

Meta submitted its proposal to EU antitrust regulators last week after ​the European Commission said it was considering an order requiring the firm to provide rivals access ⁠to WhatsApp until it wraps up an ongoing investigation into the case.

Neither side gave any details of the ​offer.

Interested parties had until May 18 to provide feedback to the Commission before it decides whether to accept Meta’s offer, ​the people said.

The offer would see Meta start charging rival AI chatbots once they hit a limit in terms of messages sent to users, the two sources added.

The wider case underscores how the EU enforcer is looking to ensure competition in new digital markets by preventing ​Big Tech from amassing market power or thwarting small rivals.

The Commission declined to comment, repeating that its priority is to ​keep the growing market of AI assistants open and competitive for innovators.

It said Meta’s offer should allow space for further talks to ‌address its ⁠concerns.

Meta reiterated earlier comments saying it has given rival AI chatbots in Europe free access to WhatsApp business Application Programming Interface (API) for a month while it seeks to resolve the issue with EU regulators.

An API is a type of software interface which determines how two software systems will interact.

Smaller rivals, however, said they were unimpressed.

The Interaction Company of California, ​developer of the Poke.com AI ​assistant, and French startup Agentik, ⁠both of which had complained to the Commission, dismissed Meta’s offer.

“Unfortunately, Meta’s current proposal is far from resolving any of the competition concerns identified in this case,” The Interaction Company ​of California said.

“If Meta does not put forward a genuinely constructive proposal without delay, ​we urge the ⁠Commission to proceed with the interim measures.”

Agentik founder Jeremy Andre said the offer discriminates against rivals as it would not apply to Meta’s own AI.

Meta’s AI chatbot, however, does not use WhatsApp’s API.

Meta introduced a policy in January allowing only its ⁠Meta AI ​assistant on WhatsApp, before amending it in March and saying rivals could ​use the social messaging app for a fee.

That triggered a second charge sheet from the EU watchdog, prompting the company to suspend fees for a ​month while it discussed its proposal with the Commission.