"The vongole minimum size is reduced from 25 millimetres (2.5 centimetres) to 22 millimetres from January 2017 for three years," European Commission spokesman Enrico Brivio told reporters.
"It may seem just a question of millimetres but in reality it's an important decision for many fishermen, in the Adriatic Sea especially," added Brivio.
The 2.5 centimetre (one inch) limit sparked outrage in Italy where it was seen as a threat to a national dish famous the world over.
The Coldiretti association of farmers and fishermen dubbed the limit as "absurd" and warned that also restricting fishermen to some 600 metres (yards) of the coastline threatened their livelihood.
Brivio insisted that relaxing the size limit showed the EU was flexible enough to respond to local conditions while the Italian government would monitor the situation to ensure the change did not harm stocks.