Switzerland’s financial regulator reportedly prevented a previous attempt by the Saudi National Bank to quadruple its stake in Credit Suisse.

The Swiss Financial Market Supervisory Authority (Finma) prevented a previous attempt by the Saudi National Bank (SNB) to increase its stake in Credit Suisse from 9.88 percent to around 40 percent, according to a report by Swiss newspaper «Blick» citing unnamed sources.

SNB was already Credit Suisse’s largest shareholder and would have had to invest a further $5 billion. It was not clear why Finma opposed the deal, the report added.

UBS agreed to buy Credit Suisse for three billion Swiss francs ($3.4 billion) on March 19. The deal converted SNB’s stake in Credit Suisse into a 0.5 percent stake in UBS.