But Charlton claim they have received payment for this season already and will seek a new sponsor ahead of the next campaign.
"It appears that Llanera have been unable to reach an agreement with their bankers on a refinancing deal," chief executive Peter Varney told the club's official website.
"The total debt seems to be around 750million euros and two banks in particular look likely to suffer significant losses.
"But our agreement was structured in a way that means we will not incur any losses in the current financial year."