European stock markets firm at open

European stocks firmed on Friday in opening deals despite the eruption of a global trade war as Brussels slapped retaliatory tariffs on the United States.

London's benchmark FTSE 100 index of major blue-chip firms rose 0.2% to 7 571.78 points compared with Thursday's closing level.

In the eurozone, Frankfurt's DAX 30 was virtually unchanged at 12 507.72, while the Paris CAC 40 gained almost 0.3% to 5 330.5 points.

"Trade wars continue to weigh," noted Markets.com analyst Neil Wilson.

"European tariffs on US imports come into effect today and the pressure does seem to be building on equities now."

As European Union tariffs on key US goods - including jeans, bourbon and motorcycles - came into effect, there were fears China and the US will carry through with their own threats, locking the world's three biggest economies in a potentially destructive face-off.

"Trade tensions remain the dominant theme," added Accendo Markets analyst Mike van Dulken.

"Clarity (is) still lacking about how far things will ultimately go between US and China, and the potential ripple effect for world trade."

The EU move was in retaliation to US President Donald Trump's decision to hit steel and aluminium imports from the bloc, and comes after Washington and Beijing traded tit-for-tat threats on hundreds of billions of dollars of goods.

There are worries a full-blown flare up could pummel the global economy just as it is getting back on its feet after the global financial crisis.