Spain's main stock market index opened its fourth consecutive session in the red on Tuesday, in what would be the worst streak since early December, infected by anxiety surrounding the quarterly results of a number of European banks.

Attention is focused on whether the banking results reveal weaknesses linked to the recent crisis in the sector - the collapse of two U.S. banks and the bailout of Swiss Credit Suisse through the merger with UBS - which has increased uncertainty about the evolution of an economy struggling with persistent inflation.

"It is foreseeable that the ECB will have to continue to prioritize the control of inflation, which remains at record levels in the underlying rate," said Renta 4 analysts in their daily analysis note.

Against this backdrop, sentiment is particularly vulnerable to falls such as that of US bank First Republic Bank, which plunged more than 20% after the close of trading on Monday, stating that deposits plummeted by more than $100 billion in the first quarter and that it is exploring options such as restructuring its balance sheet.

Among European banks, it was Switzerland's UBS that overshadowed the day with a 52% drop in its quarterly profit due to higher reserves to end its involvement in toxic mortgages, at a time when it is preparing to integrate its ill-fated domestic competitor Credit Suisse into its accounts.

For its part, Santander lost 2.68% after publishing its results, in a session in which the sector as a whole fell due to the climate of anxiety.

In this context, at 07:05 GMT on Tuesday, the selective Spanish stock market Ibex-35 fell 88.10 points, 0.94%, to 9,318.30 points. If it closes with the same trend, this would be the fourth session of the longest negative streak since December 2-8.

The FTSE Eurofirst 300 index of large European stocks was down 0.39%.

In the banking sector, BBVA fell 2.05%, Caixabank dropped 1.66%, Sabadell fell 2.06%, Bankinter lost 1.00% and Unicaja Banco lost 2.07%.

Among the large non-financial stocks, Telefónica fell 0.40%, Inditex dropped 0.64%, Iberdrola lost 0.21%, Cellnex gained 0.08%, and the oil company Repsol rose 0.18%.

(Information by Flora Gómez; edited by Tomás Cobos)