Europe open: Stocks down, traders eye key levels for Brent and euro

At 0915 GMT the benchmark Stoxx 600 was losing 0.89% to 372.31, the German Dax was down 0.75% to 11,872.38 and France's Cac-40 was retreating 0.83% to 4,960.68.

The euro/dollar was changing hands slightly lower as of 0919 GMT, slipping 0.34% to 1.0782.

Analysts said both euro/dollar and Brent futures were near levels - 1.0830 and $50.25 per barrel, respectively - that if breached might see both extend their recent moves.

"The driver for the sell-off is uncertainty about implementation of the US policies that have driven the optimism that fuelled the Trump reflation trade, ushering markets to recent highs. After two months in office, markets want proof not just promises, fearful that the Healthcare reform Trump is using to put his stamp on the presidency could delay the tax cuts and infrastructure spending markets desire so much more," said Mike van Dulken, Head of Research at Accendo Markets.

On the economic calendar for Wednesday are January euro area current account data at 1000 GMT, together with the latest batch of existing home sales data in the US for February at 1400 GMT.

Gemalto NV crashed 20% after slashing its outlook for 2017, telling shareholders to expect to see a decline in revenues.

Stock in Dutch lender ING were also unloved after it disclosed that it was the target of a criminal investigation.