The Spanish National Commission on Markets and Competition, also known as CNMC, fined CaixaBank SA, Banco Santander SA, Banco Bilbao Vizcaya Argentaria SA and Banco de Sabadell SA a combined €91 million for colluding to fix the conditions of interest-rate derivatives offered to their clients.

An investigation found that the four banks had conspired to offer interest-rate derivatives with conditions that were different from those previously agreed with their clients, while making it appear that they were each consulting the market for the price of the derivatives. The issues were first flagged by a company specializing in the construction of wind-energy-related infrastructure.

CaixaBank and Santander will pay fines of €31.8 million and €23.9 million, respectively, while BBVA and Sabadell will pay €19.8 million and €15.5 million.