Atletico Madrid lodged an appeal Monday against a one-year transfer ban imposed by FIFA over their dealing in under-age players.
The ban starts from the July transfer window this year and finishes with the January transfer market in 2017.
Real Madrid were hit with the same punishment.
Atletico were also fined 900,000 Swiss francs (820,000 euros) and Real 360,000 (330,000 euros). However, both clubs are still allowed to sign players until the end of the month.
Atletico in a statement announced that they had “lodged an appeal against the decision by FIFA’s disciplinary commission”.
World football’s governing body FIFA said the alarm was raised over the two clubs by FIFA’s Transfer Matching System and its disciplinary committee completed the inquiry.
Under international football rules, players under 18 cannot be transferred to another country, except in limited circumstances. All transfers need the approval of a special FIFA committee.
European champions Barcelona have just completed a one year ban for similar reasons.