A Spanish court opened a fraud case on Wednesday against former executives of state-rescued lender Bankia, including one-time IMF chief Rodrigo Rato.

The lawsuit was brought by one of Spain's smaller political parties and accuses 33 officials including Rato of fraud, price-fixing and falsifying accounts.

Rodrigo Rato is a former government minister who stood down as Bankia chairman in May.

Under Spanish law, the crimes carry jail sentences ranging from six months to six years but commentators said that while corporate corruption cases grab the headlines in Spain, they rarely resulted in convictions.

"It will be a long-running, complicated case," said Pedro Schwartz, economics professor at San Pablo University in Madrid.

Spaniards are angry with the political and business elites in general as the government of Prime Minister Mariano Rajoy has imposed austerity policies and had to seek European Union aid to save a series of banks including Bankia from collapse.

However, fury is particularly directed at Bankia as hundreds of thousands of small savers were persuaded to buy shares in the lender when it was floated on the stock market in 2011, only to see their investments all but wiped out in less than a year.

Bankia's new management has requested a €19 billion bailout.

In the case brought by the Union, Progress and Democracy party, the High Court is demanding that Rato and the other executives appear in person.

It also wants former Bank of Spain governor Miguel Angel Fernandez Ordonez to appear as a witness, alongside the partner in auditor Deloitte who was in charge of signing off Bankia's results and the chairman of the Spanish stock market regulator.