Weekly Losses for UK's Stock Markets Amid U.S.-Iran Tensions and Economic Warnings

The UK's main stock indexes faced weekly downturns as investors gauged renewed signs of U.S.-Iran peace negotiations. Compounded by a Bank of England warning on global stock pressures, the market sentiment remained cautious.

The FTSE 100, a blue-chip index, ended 0.8% lower at 10,379.08 points, marking its first weekly decline in five weeks, erasing gains made since the U.S.-Iran ceasefire earlier this month. The FTSE 250 also fell 0.8% while Iran's foreign minister headed to Islamabad to discuss possible steps towards renewing U.S.-Iran talks, according to Pakistani government sources.

Investors were jittery with crude oil prices lingering above $100 per barrel, amid uncertainty over the Strait of Hormuz. The Bank of England's Deputy Governor, Sarah Breeden, warned that stock markets globally might fall as current valuations do not adequately account for various economic risks. Rising oil prices adversely affected airline shares, with Wizz Air dropping 3.3%. Among banks, Barclays and HSBC saw declines of 0.9% and 1.3%, respectively, while pharma giants AstraZeneca and GSK also fell significantly.