ISTANBUL

European stock markets ended the week down as London's Heathrow Airport was closed for a large chunk of the day Friday due to a power outage caused by a fire at a nearby electrical substation.

The closure caused more than 100,000 British Airways customers to have their flights cancelled.

Later in the day, the airport announced that it would resume some flights.

In a statement, a Heathrow spokesperson apologized for the inconvenience and confirmed that efforts to restore operations have been ongoing.

The travel and leisure industry saw a 1.6% decline. International Airlines Group, the parent company of British Airways, was down about 1.9%.

Also on Friday, Germany's upper house, the Bundesrat, approved constitutional changes that will enable major funding boosts for defense and infrastructure.

Expenditures in some fields exceeding 1% of the country’s GDP will be exempt from the constitutional “debt brake” rule. Previously, the country’s basic law capped government borrowing at 0.35% of GDP.

Another approved measure establishes a €500 billion ($542 billion) special fund for infrastructure investments and climate protection.

The pan-European Stoxx 600 fell 0.60% or 3.31 points to 549.67.

Britain’s FTSE 100 lost 0.63% – 55.20 points – to close the day at 8,646.79, while Germany's DAX 40 index fell 0.47%, or 107.47 points, to 22,891.68

France's CAC 40 also fell 0.63%, or 51.25 points, to 8,042.95, and Italy's FTSE MIB 30 index slipped 0.39% to 39,035.71 in a 152.46-point fall.