By John S. McClenahen Greece is the latest European nation to adopt the euro, the common currency now of 12 of the European Union's 15 member countries. Euro notes and coins will not appear for another year, although many business and banking transactions, including invoicing and bidding, as well as corporate annual reports, are already denominated in euros. In addition to Greece, the countries using the euro -- what economists have dubbed the "eurozone" -- are Austria, Belgium, France, Finland, Germany, Ireland, Italy, Luxembourg, the Netherlands, Portugal, and Spain. The euro, which debuted on Jan. 1, 1999, with a value of US$1.17, took an exchange rate beating during 2000, falling at one point below $0.85, a 27% decline. A forecast from Merrill Lynch & Co., New York, shows the European currency doing better relative to the U.S. dollar this year, with an average exchange rate between $0.91 and $0.95 in each calendar quarter of 2001.