Refined oil products such as petrol, diesel and heating oil form the biggest chunk of Dutch exports and they have become more important over the past 10 years, the national statistics office CBS said on Thursday.

Specialist technology, such as chip making machinery and prepared foods such as baby milk formula, have also increased their share of the export total, the CBS said.

The value of oil exports have risen from €20bn to €38bn over the past 10 years, despite oil price shifts. Oil products  now account for 9% of Dutch exports, compared with 7% 10 years ago.

By contrast, gas and flowers, both traditional Dutch exports, have declined in importance. Cut flowers accounted for 2.8% of total exports in 2005, but this had fallen to 2.3% last year.

The importance of baby milk has almost doubled from 0.8% to 1.4% over the ten year period, the CBS said.