Not sure about any other companies, but this is ArGo in Greece:
Careers - In the air - ArGo Airways
POSITION: FIRST OFFICER
MINIMUM REQUIREMENTS:
a. JAR FCL/CLP with credit ATPL theory (frozen ATPL).
b. Current Multi Engine & IFR Rating plus Seaplane Rating.
All candidates should have valid medicals, IFR & multi engine ratings. Captain applicants should have currency on type and at least six months remaining on their ratings.
To upgrade from first Officer to Captain, candidates must have at least 500 hrs on the DHC-6 or DHC-3T on floats before they begin the PIC under supervision training. A minimum of 100 hrs and 200 sectors are required as Captain under supervision before being released as a line captain.
Note: Candidates that do not meet all the requirements need not apply.