The Ibex-35 opened slightly higher on Wednesday, amid a cautious turn in risk appetite weighing on Wall Street and Asian markets and rising tensions in the Middle East.

"The key will be in the Spanish index's ability to sustain (the) rebound as selling starts to take hold in equities," said Diego Morin, market analyst at IG in a note to clients.

In the macroeconomic landscape, investors will turn their attention on Wednesday to the release of the Federal Reserve's December meeting minutes and the ISM survey on the U.S. manufacturing sector.

At 0815 GMT on Wednesday, Spain's selective Ibex-35 stock market index was up 20.00 points, or 0.19%, to 10,201.20 points, while the FTSE Eurofirst 300 index of large European stocks was up 0.20%.

In the banking sector, Santander rose 0.40%, BBVA gained 0.45%, Caixabank advanced 0.60%, Sabadell gained 0.61%, Bankinter gained 0.57%, and Unicaja Banco rose 0.66%.

Among the large non-financial stocks, Telefónica gained 0.83%, Inditex advanced 0.05%, Iberdrola gained 0.76%, Cellnex fell 0.03%, and the oil company Repsol lost 0.30%.

(Information by Benjamín Mejías Valencia; edited by Natalia Siniawski)