European stocks have tumbled this morning as investors enter the second quarter in a febrile atmosphere of trade tensions and mounting pressure on big technology companies.

The pan-European STOXX 600 fell 0.7%, while Germany's DAX declined 0.8%, with industrials, consumer staples and financials the biggest weights.

In Dublin the ISEQ was 0.6% lower shortly before 9am.

Across Europe, the tech sector has dropped 1%, weighed by chipmakers after an overnight report that Apple plans to replace Intel chips in Macs with its own.

The STOXX 600 index has fallen 8% in the past three weeks as anxiety grew over big tech companies with the focus on Facebook's use of data, and regulation of Amazon.

Reports of Apple increasingly going down the "insourcing" route have dented shares in Apple suppliers around the world, most notably Europe's Dialog Semiconductor, which has shed more than 60% in the past year.

This morning ams have led the falls, down 2.8%, while STMicro declined 2.3% and Infineon fell 1.7%.

Risk appetite is poor across the board, as European investors follow US and Asian investors to the exit after China retaliated against US tariffs.

Outside the tech sector, food services group Sodexo is the worst-performing on the STOXX, down 3.8% after Goldman Sachs cut the stock to "neutral", citing competition and cost inflation.

Acquisition news also continued to move the European market.

Eurofins Scientific shares fell 2.9%, the worst performers on the STOXX, after the firm acquired LabFrontier in South Korea.

Basic resources and oil & gas stocks were a rare bright spot, making gains as metals prices rose.