Uefa is aware of the referral made by the European Super League to the European Court of Justice
Uefa plans a "robust" defence of its position after the European Super League claimed the governing body had broken European Union competition law.
On Monday, the European Court of Justice said it had received a referral from the European Super League (ESL).
The referral claims Uefa and Fifa acted unlawfully in trying to block the ESL's creation and in threatening to sanction clubs still involved in the project.
Uefa said it remained "confident" in its position.
European football's governing body said: "Uefa takes note of the announcement by the European Court of Justice of the referral from a Madrid court on the so-called European Super League, notwithstanding the withdrawal of nine of its founding member clubs.
"Uefa is confident in its position and will defend it robustly."
- European Super League timeline – football's volatile 72 hours
Twelve of Europe's biggest clubs announced on 18 April that they had formed a new competition, and within hours had informed Uefa and Fifa of pre-emptive measures the ESL had taken to block any challenges to its foundation.
However, the new league effectively collapsed within 72 hours as founder clubs withdrew one by one, starting with the six English Premier League clubs involved.
Nine of the clubs entered a new peace deal with Uefa on 7 May, but the three who have not renounced the ESL – Barcelona, Real Madrid and Juventus – face sanctions after disciplinary proceedings were opened on 25 May.
The trio issued a joint statement the following day, describing the disciplinary action as "incomprehensible" and that football faced an "inevitable downfall" without major reform.