Negotiations between the United States and Iran have fallen apart, triggering declines in European stock markets on Friday. The AEX index closed down 0.3 percent at 1078.2 points. The price of oil experienced a rebound, benefiting Shell shares which rose 1.1 percent despite a challenging week. This increase in oil prices is directly linked to the uncertainty surrounding a potential Iran nuclear deal. US markets remained closed for a holiday. The outcome of the talks introduces renewed volatility to global financial markets and energy sectors. Investors are reacting to the diminished prospects of increased Iranian oil supply.