Madrid, Sep 9 (IANS): The governing body of world football, FIFA, on Thursday ratified the sanction it imposed on Spanish clubs Real Madrid and Atletico Madrid for irregularities involving players in their youth systems.

Neither of the two clubs will now be able to make any new signings until January 2018 for, "having infringed the current regulations regarding the international transfers of players younger than 18 years old", Xinhua news agency reported.

Both clubs were originally sanctioned by not being allowed to purchase players for two transfer windows by FIFA in January for the irregularities in their youth system, but both appealed against the decision.

These appeals have now been rejected although Real Madrid have already announced they will appeal to the Tribunal for Arbitration in Sport (TAS) and it is likely Atletico will do the same.

However, given that their offences are similar to those which saw FC Barcelona banned from registering players in the January 2015 and summer 2015, it is unlikely they will succeed in their aims.

Atletico Madrid have also been condemned to pay a fine of 900,000 Swiss Franks ($925,902), while Real Madrid have been fined 360,000 ($370,360) by FIFA.