At the start of this year, Brussels' antitrust chief Margrethe Vestager warned data-hoarding tech giants that she was looking at them very closely—even though she was yet to spot a "competition problem." In June, Microsoft—with its planned buyout of LinkedIn—caught the eye of the Dane, who has been examining whether the £18.5 billion ($26.2 billion) deal should clear a regulatory hurdle in the 28-member-state bloc.

On Wednesday, a spokesperson at Vestager's office—which has been looking at the business activities of the two firms to determine whether the proposed merger could be bad for competition—confirmed to Ars that it had "received a commitments proposal" from Microsoft and LinkedIn.

It comes after Salesforce boss Marc Benioff, who had reportedly been considering a takeover of LinkedIn before Microsoft stepped in, told Recode that he had pushed the US Federal Trade Commission to probe the proposed merger. The deal has already received regulatory clearance Stateside, however.

He claimed that Microsoft's play for LinkedIn was an anticompetitive swoop on the data pumped into business productivity software. And Benioff has apparently made his feelings known to Vestager. It's understood that Salesforce submitted a response to a European Commission questionnaire, which sought views from interested parties who may have been concerned about LinkedIn being wedded to Microsoft.

In October, the EC said: "On preliminary examination, the commission finds that the notified transaction could fall within the scope of the Merger Regulation. However, the final decision on this point is reserved."

Salesforce foreshadowed its submission to the bloc's competition boss in late September, when its legal chief Burke Norton argued: "By gaining ownership of LinkedIn’s unique dataset of over 450 million professionals in more than 200 countries, Microsoft will be able to deny competitors access to that data, and in doing so obtain an unfair competitive advantage."

Vestager's office is now looking at Microsoft's so-called "commitments proposal," and will seek the views of the company's rivals. Her spokesperson told us that "the new decision deadline is 6 December."

Microsoft declined to comment on the makeup of its concessions package to the commission when quizzed by Ars.