The state-controlled Brazilian oil giant Petrobras is studying whether to drill for oil off Cuban shores, while the Odebrecht construction firm is heading a huge revamp of the port of Mariel, west of Havana, into the island's main commercial port.Brazil's state-run National Development Bank has given $300m (£196m) to Odebrecht to build new roads, rail lines, wharves and warehouses at Mariel, best known as the site of a 1980 exodus in which thousands of Cubans fled to the US in boats.
