Italcementi SpA said it bought MV White Shark, a cement carrier with a net transport capacity of 29,000dwt.   The new ship was acquired through Medcem, Italcementi’s 50:50 joint venture with logistics partner Gruppo Romeo, for an overall investment of about US$23m, it said in a statement.  The cement maker first entered in the shipping business in April when Medcem launched MV Turbocem, a 5500dwt carrier in which it invested Euro 6.5m. Turbocem operates in the Mediterranean and White Shark in the Atlantic markets.