FRANKFURT, Germany (AP) — Jitters over a possible U.S.-led trade war are weighing on a key index of sentiment among investment professionals in export-oriented Germany.

The ZEW index sagged to 5.1 points in March from 17.8 points in February. The main reason was a more pessimistic outlook for coming months, while assessments of how things are currently slipped by less.

The survey is based on interviews with investment analysts on how they see things shaping up in Europe's largest economy.

The ZEW research institute in Munich said Tuesday that "concerns over a U.S.-led global trade conflict have made the experts more cautious in their prognoses. "

New import taxes on steel and aluminum proposed by President Donald Trump have raised concerns that other trade partners including the European Union may retaliate.