Markets around the world took a dive Tuesday on fears that Europe’s debt deal could disintegrate. In the U.S., the Dow and Nasdaq each opened down more than 2 percent. Greek prime minister George Papandreou said yesterday that his nation will hold a referendum on the European Union’s bailout package, saying it’s up to the people to decide whether to adopt the deal. The package would give the cash-strapped nation $182 billion, but also imposes unpopular austerity measures that analysts say could further threaten the eurozone. A survey Saturday showed that nearly 60 percent of Greeks see the new EU bailout as negative or probably negative.