* MSCI Asia ex-Japan edges up, Nikkei opens down 0.2 pct. * Euro steadies vs dollar after Monti reassures. Asian shares and the euro steadied on Tuesday, drawing support from expectations that the U.S. Federal Reserve will take fresh economic stimulus measures this week. MSCI's broadest index of Asia-Pacific shares outside Japan nudged up 0.1 percent to a 16-month high, led by Australian shares which gained 0.3 percent to their highest in nearly two months on a rise in metals and oil prices and hopes for Fed action. South Korean shares opened 0.3 percent higher while Japan's Nikkei stock average opened down 0.2 ... (full story)