Attica Group’s keynote deal to take full control of Hellenic Seaways (HSW), Greece’s biggest ferry company, may face regulatory hurdles.

The agreement to buy the 48.5% stake in HSW that Attica does not already own from Italy's Grimaldi Group creates a market player to dwarf any other domestically.

Attica and HSW combined would have a fleet of about 30 conventional passengerships, fast ferries and catamarans.