"The BPI expressed, in the course of the proceedings, its disagreement as to the imputation of that infringement and its grounds, and decided to lodge an appeal against the decision now taken by that authority in the Court of Competition, Regulation and Supervision," the bank said in a statement.

According to the statement, BPI disputes that "the alleged exchange of information occurred in the manner alleged in the accusatory ruling and considers, in particular, that the information in question, by its nature, could not produce anti-competitive effects and did not in any way damage customers' interests."

These arguments have been expressed during the proceedings started by the Competition Authority (AdC), it states.

Three other banks that had fines imposed for similar reasons - BCP, Caixa Geral de Depósitos (CGD) and Santander Totta - have already said that they will appeal against them.

The AdC announced on Monday that it had found 14 banks guilty and imposed fines of €225 million per concerted practice of sensitive information on credit over more than a decade, from 2002 to 2013.

"In this scheme, each bank provided the others with sensitive information about their commercial offerings, indicating, for example, the [interest rate] spreads to be applied in the near future on housing loans or the amounts of credit granted in the preceding month - data that otherwise would not be accessible to competitors," the AdC said.

CGD is the bank that faced the highest fine, of €82 million, followed by BCP, which was told to pay €60 million.

Santander Totta has been fined €35 million, and must also foot the bill for the €600,000 fine of Banco Popular, which it has bought in the meantime.

BPI was fined €30 million and Montepio – which was initially fined €26 million – saw that penalty reduced to €13 million because it has already signed up for the clemency programme.

Barclays, meanwhile, is exempt from any fine because it was the institution that reported the alleged cartel.

Banco Espírito Santo – which was wound up several years ago – was fined €700,000. Its successor institution (currently in liquidation) must pay that, not Novo Banco, which took over the viable commercial business, since the latter took on BES responsibilities excluding those "arising from fraud or violation of regulatory, penal or counter-administrative provisions, with the exception of active fiscal contingencies," the AdC explained on Monday.

Crédito Agrícola faces a fine of €350,000.

As for other banks, according to a report in Wednesday’s Expresso newspaper, BBVA faces a fine of €2.5 million, BIC a fine of €500,000 (due to BPN, which it has acquired in the meantime), Deutsche Bank €350,000, UCI €150,000 and Banif €1,000.