PUBLISHED: 12 JUL 2014 02:49:17 | UPDATED: 15 JUL 2014 14:08:35

KAREN MALEY

Are storm clouds beginning to amass over European markets?

This week Portuguese bond yields spiked and stocks sagged after shares in Portugal’s biggest bank, Banco Espirito Santo, were suspended from trading after “ongoing material difficulties” in its parent company.

Demonstrating how nervous investors are about the euro zone banking sector, the turmoil quickly spread through southern Europe, as a Spanish bank called off a planned bond sale and trading in several Italian banks was briefly halted.