BUENOS AIRES, Feb 18 (Reuters) - Argentine banking and financial services company Grupo Supervielle saw its shares spike over 50% on Thursday on rumors of a potential takeover, hitting the highest level since 2018 before easing back to be up around 14%.

Traders said that unsubstantiated talk of a potential sale to a Brazilian buyer had pushed up the shares as well as the firm's American Depositary Receipts (ADRs).

"There is a rumor that it is being sold to a powerful group in Brazil, but nothing is known," one trader told Reuters.

An external press official for the firm told Reuters that they "did not have this information" and that the issue of the share price jump was been analyzed internally. The person added there was no "relevant facts" to divulge currently.

"For everyone it has been very surprising," the person added.

(Reporting by Jorge Otoala; Writing by Adam Jourdan Editing by Chizu Nomiyama and Bernadette Baum)