Two are confirmed dead and four are missing from the 3,350-dwt Gokbal (built 2011) which was on a coastal voyage between the Italian ports of Ravenna and Brindisi.
Storms were reported at the time the Gokbal was in collision with the 4,452-dwt general cargoship Lady Aziza (built 1991.
The Italian coast guard said the incident happened in poor visibility on Sunday a mile off Italy’s Adriatic coastline.
Difficult weather conditions are hampering the search for the missing crewmen who are said to be Turkish.
Five survivors from the Gokbal are recovering in a Ravenna hospital and have been visited by the Turkish consul general from Milan.
No injuries are reported to the crew of the Lady Aziza.
The collision happened during the same storms that have afflicted the Greek ro-ro ferry Norman Atlantic.
The Gokbal traded as part of the fleet of Istanbul based Cetinkaya Denizcilik Transport while the Lady Aziza is operated by KMF Shipping with a registered address in St Kitts & Nevis.